| Property Portfolio - Gross Investment (Details) - USD ($)$ in Thousands
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6 Months Ended | 12 Months Ended | 
| Mar. 20, 2020 | Mar. 04, 2020 | Feb. 27, 2020 | Feb. 13, 2020 | Dec. 17, 2019 | Nov. 15, 2019 | Oct. 31, 2019 | Oct. 25, 2019 | Oct. 01, 2019 | Sep. 26, 2019 | Aug. 23, 2019 | Aug. 14, 2019 | Aug. 06, 2019 | Aug. 05, 2019 | Aug. 01, 2019 | Jul. 12, 2019 | Jun. 30, 2020 | Dec. 31, 2019 | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Beginning Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 905,529 | $ 647,550 | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 91,347 | 257,979 | 
| Capitalized costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 460 | 1,860 | 
| Ending Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 996,876 | 905,529 | 
| Zachary [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,683 | 
| Gilbert and Chandler [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 16,259 | 
| Las Vegas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 22,502 | 
| Oklahoma Northwest [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 28,207 | 
| Mishawaka [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 16,103 | 
| Surprise [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 28,682 | 
| San Marcos [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 12,000 |  | 11,974 | 
| Lansing [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 11,100 |  |  | 11,368 | 
| Bannockburn [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 6,800 |  |  |  | 6,977 | 
| Aurora [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  | $ 12,600 |  |  |  |  | 12,557 | 
| Livonia [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  | $ 10,400 |  |  |  |  |  | 10,592 | 
| Gilbert [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  | $ 5,600 |  |  |  |  |  |  | 5,592 | 
| Morgantown [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  | $ 8,000 |  |  |  |  |  |  |  | 7,950 | 
| Beaumont [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  | $ 33,700 |  |  |  |  |  |  |  |  | 33,739 | 
| Bastrop [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  | $ 12,100 |  |  |  |  |  |  |  |  |  | 12,065 | 
| Panama City [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  | $ 13,000 |  |  |  |  |  |  |  |  |  |  | 12,976 | 
| Jacksonville [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  | $ 8,900 |  |  |  |  |  |  |  |  |  |  |  | 8,869 | 
| Greenwood [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  | $ 5,800 |  |  |  |  |  |  |  |  |  |  |  |  | 5,848 | 
| Asc 842 Reclassification [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| ASC Topic 842 Reclassification |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (824) | 
| High Point Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  | $ 25,100 |  |  |  |  |  |  |  |  |  |  |  |  | 25,081 |  | 
| Clinton Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  | $ 11,600 |  |  |  |  |  |  |  |  |  |  |  |  |  | 11,619 |  | 
| West Allis Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  | $ 9,100 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 9,357 |  | 
| Grand Rapids Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions | $ 22,700 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 22,790 |  | 
| Dumfries [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 22,040 |  | 
| Land [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Beginning Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 95,381 | 63,710 | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8,935 | 31,671 | 
| Capitalized costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4 | 0 | 
| Ending Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 104,316 | 95,381 | 
| Land [Member] | Zachary [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Land [Member] | Gilbert and Chandler [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,616 | 
| Land [Member] | Las Vegas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,479 | 
| Land [Member] | Oklahoma Northwest [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,364 | 
| Land [Member] | Mishawaka [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,924 | 
| Land [Member] | Surprise [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,738 | 
| Land [Member] | San Marcos [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,322 | 
| Land [Member] | Lansing [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,202 | 
| Land [Member] | Bannockburn [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 763 | 
| Land [Member] | Aurora [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,521 | 
| Land [Member] | Livonia [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 980 | 
| Land [Member] | Gilbert [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,408 | 
| Land [Member] | Morgantown [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 883 | 
| Land [Member] | Beaumont [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,022 | 
| Land [Member] | Bastrop [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,975 | 
| Land [Member] | Panama City [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,559 | 
| Land [Member] | Jacksonville [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,023 | 
| Land [Member] | Greenwood [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 892 | 
| Land [Member] | Asc 842 Reclassification [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| ASC Topic 842 Reclassification |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Land [Member] | High Point Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,749 |  | 
| Land [Member] | Clinton Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 664 |  | 
| Land [Member] | West Allis Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 974 |  | 
| Land [Member] | Grand Rapids Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,947 |  | 
| Land [Member] | Dumfries [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,597 |  | 
| Building [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Beginning Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 693,533 | 518,451 | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 62,274 | 175,082 | 
| Capitalized costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 281 | 1,179 | 
| Ending Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 755,807 | 693,533 | 
| Building [Member] | Zachary [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,336 | 
| Building [Member] | Gilbert and Chandler [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 11,643 | 
| Building [Member] | Las Vegas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 15,277 | 
| Building [Member] | Oklahoma Northwest [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 19,501 | 
| Building [Member] | Mishawaka [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10,084 | 
| Building [Member] | Surprise [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 18,737 | 
| Building [Member] | San Marcos [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6,934 | 
| Building [Member] | Lansing [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,681 | 
| Building [Member] | Bannockburn [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,566 | 
| Building [Member] | Aurora [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,446 | 
| Building [Member] | Livonia [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,629 | 
| Building [Member] | Gilbert [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,027 | 
| Building [Member] | Morgantown [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,286 | 
| Building [Member] | Beaumont [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 24,836 | 
| Building [Member] | Bastrop [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8,436 | 
| Building [Member] | Panama City [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8,682 | 
| Building [Member] | Jacksonville [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,846 | 
| Building [Member] | Greenwood [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,956 | 
| Building [Member] | Asc 842 Reclassification [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| ASC Topic 842 Reclassification |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Building [Member] | High Point Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 20,367 |  | 
| Building [Member] | Clinton Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6,551 |  | 
| Building [Member] | West Allis Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,687 |  | 
| Building [Member] | Grand Rapids Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 17,341 |  | 
| Building [Member] | Dumfries [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10,047 |  | 
| Site Improvements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Beginning Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 9,912 | 6,880 | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,681 | 3,032 | 
| Capitalized costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 | 170 | 
| Ending Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 11,593 | 9,912 | 
| Site Improvements [Member] | Zachary [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 103 | 
| Site Improvements [Member] | Gilbert and Chandler [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Site Improvements [Member] | Las Vegas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 244 | 
| Site Improvements [Member] | Oklahoma Northwest [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 143 | 
| Site Improvements [Member] | Mishawaka [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 74 | 
| Site Improvements [Member] | Surprise [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 228 | 
| Site Improvements [Member] | San Marcos [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 126 | 
| Site Improvements [Member] | Lansing [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 185 | 
| Site Improvements [Member] | Bannockburn [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 132 | 
| Site Improvements [Member] | Aurora [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 308 | 
| Site Improvements [Member] | Livonia [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 201 | 
| Site Improvements [Member] | Gilbert [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 62 | 
| Site Improvements [Member] | Morgantown [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 373 | 
| Site Improvements [Member] | Beaumont [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 399 | 
| Site Improvements [Member] | Bastrop [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 64 | 
| Site Improvements [Member] | Panama City [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 220 | 
| Site Improvements [Member] | Jacksonville [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Site Improvements [Member] | Greenwood [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Site Improvements [Member] | Asc 842 Reclassification [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| ASC Topic 842 Reclassification |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Site Improvements [Member] | High Point Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 440 |  | 
| Site Improvements [Member] | Clinton Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 342 |  | 
| Site Improvements [Member] | West Allis Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 137 |  | 
| Site Improvements [Member] | Grand Rapids Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 470 |  | 
| Site Improvements [Member] | Dumfries [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 289 |  | 
| Tenant improvements [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Beginning Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 33,909 | 15,357 | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7,982 | 18,552 | 
| Capitalized costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 172 | 511 | 
| Ending Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 41,891 | 33,909 | 
| Tenant improvements [Member] | Zachary [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 409 | 
| Tenant improvements [Member] | Las Vegas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,205 | 
| Tenant improvements [Member] | Oklahoma Northwest [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,044 | 
| Tenant improvements [Member] | Mishawaka [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,798 | 
| Tenant improvements [Member] | Surprise [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,119 | 
| Tenant improvements [Member] | San Marcos [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 404 | 
| Tenant improvements [Member] | Lansing [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 667 | 
| Tenant improvements [Member] | Bannockburn [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,134 | 
| Tenant improvements [Member] | Aurora [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 603 | 
| Tenant improvements [Member] | Livonia [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 442 | 
| Tenant improvements [Member] | Gilbert [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 362 | 
| Tenant improvements [Member] | Morgantown [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 506 | 
| Tenant improvements [Member] | Beaumont [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,036 | 
| Tenant improvements [Member] | Bastrop [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 276 | 
| Tenant improvements [Member] | Panama City [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,036 | 
| Tenant improvements [Member] | High Point Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 869 |  | 
| Tenant improvements [Member] | Clinton Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,578 |  | 
| Tenant improvements [Member] | West Allis Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 98 |  | 
| Tenant improvements [Member] | Grand Rapids Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 450 |  | 
| Tenant improvements [Member] | Dumfries [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,815 |  | 
| Intangibles [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Beginning Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 72,794 | 43,152 | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10,475 | 29,642 | 
| Capitalized costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Ending Balance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 83,269 | 72,794 | 
| Intangibles [Member] | Zachary [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 835 | 
| Intangibles [Member] | Gilbert and Chandler [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Intangibles [Member] | Las Vegas [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,297 | 
| Intangibles [Member] | Oklahoma Northwest [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,155 | 
| Intangibles [Member] | Mishawaka [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,223 | 
| Intangibles [Member] | Surprise [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,860 | 
| Intangibles [Member] | San Marcos [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,188 | 
| Intangibles [Member] | Lansing [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,633 | 
| Intangibles [Member] | Bannockburn [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,382 | 
| Intangibles [Member] | Aurora [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,679 | 
| Intangibles [Member] | Livonia [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,340 | 
| Intangibles [Member] | Gilbert [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 733 | 
| Intangibles [Member] | Morgantown [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 902 | 
| Intangibles [Member] | Beaumont [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,446 | 
| Intangibles [Member] | Bastrop [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,314 | 
| Intangibles [Member] | Panama City [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,479 | 
| Intangibles [Member] | Jacksonville [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Intangibles [Member] | Greenwood [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 
| Intangibles [Member] | Asc 842 Reclassification [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| ASC Topic 842 Reclassification |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (824) | 
| Intangibles [Member] | High Point Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,656 |  | 
| Intangibles [Member] | Clinton Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,484 |  | 
| Intangibles [Member] | West Allis Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 461 |  | 
| Intangibles [Member] | Grand Rapids Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,582 |  | 
| Intangibles [Member] | Dumfries [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Property, Plant and Equipment [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Acquisitions |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 4,292 |  |