| Condensed Consolidated Statements of Equity (Parentheticals) - $ / shares | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
| Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | |
| Condensed Consolidated Statements of Equity | ||||
| Dividends to common stockholders | $ 0.205 | $ 0.20 | $ 0.615 | $ 0.60 | 
| Dividends to preferred stockholders | $ 0.46875 | $ 0.46875 | $ 1.40625 | $ 1.40625 | 
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- Definition Aggregate dividends declared during the period for each share of common stock outstanding. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Aggregate dividends declared during the period for each share of preferred stock outstanding. No definition available. 
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| X | ||||||||||
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- References No definition available. 
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