Stockholders' Equity Schedule of Preferred Dividends Declared (Details) - $ / shares |
3 Months Ended | |||||
|---|---|---|---|---|---|---|
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
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| Series A Preferred Stock [Member] | ||||||
| Class of Stock [Line Items] | ||||||
| Declaration Date | Sep. 20, 2018 | Jun. 19, 2018 | Mar. 20, 2018 | Dec. 14, 2017 | Sep. 14, 2017 | Jun. 15, 2017 |
| Record Date | Oct. 12, 2018 | Jul. 12, 2018 | Apr. 12, 2018 | Jan. 12, 2018 | Oct. 12, 2017 | Jul. 12, 2017 |
| Payment Date | Oct. 29, 2018 | Jul. 27, 2018 | Apr. 27, 2018 | Jan. 29, 2018 | Oct. 27, 2017 | Jul. 27, 2017 |
| Dividends declared per preferred share (in usd per share) | $ 0.507810 | $ 0.507810 | $ 0.507810 | $ 0.507810 | $ 0.507810 | $ 0.750430 |
| Series B Preferred Stock [Member] | ||||||
| Class of Stock [Line Items] | ||||||
| Declaration Date | Sep. 20, 2018 | Jun. 19, 2018 | Mar. 20, 2018 | Dec. 14, 2017 | Sep. 14, 2017 | |
| Record Date | Oct. 12, 2018 | Jul. 12, 2018 | Apr. 12, 2018 | Jan. 12, 2018 | Oct. 12, 2017 | |
| Payment Date | Oct. 29, 2018 | Jul. 27, 2018 | Apr. 27, 2018 | Jan. 29, 2018 | Oct. 27, 2017 | |
| Dividends declared per preferred share (in usd per share) | $ 0.476560 | $ 0.476560 | $ 0.476560 | $ 0.476560 | $ 0.518920 | |
| Series C Preferred Stock [Member] | ||||||
| Class of Stock [Line Items] | ||||||
| Declaration Date | Sep. 20, 2018 | Jun. 19, 2018 | Mar. 20, 2018 | Dec. 14, 2017 | ||
| Record Date | Oct. 12, 2018 | Jul. 12, 2018 | Apr. 12, 2018 | Jan. 12, 2018 | ||
| Payment Date | Oct. 29, 2018 | Jul. 27, 2018 | Apr. 27, 2018 | Jan. 29, 2018 | ||
| Dividends declared per preferred share (in usd per share) | $ 0.453130 | $ 0.453130 | $ 0.453130 | $ 0.302080 | ||
| Series D Preferred Stock [Member] | ||||||
| Class of Stock [Line Items] | ||||||
| Declaration Date | Sep. 20, 2018 | |||||
| Record Date | Oct. 01, 2018 | |||||
| Payment Date | Oct. 15, 2018 | |||||
| Dividends declared per preferred share (in usd per share) | $ 0.484375 | |||||
| Series E Preferred Stock [Member] | ||||||
| Class of Stock [Line Items] | ||||||
| Declaration Date | Sep. 20, 2018 | |||||
| Record Date | Oct. 01, 2018 | |||||
| Payment Date | Oct. 15, 2018 | |||||
| Dividends declared per preferred share (in usd per share) | $ 0.468750 | |||||
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Date the declared dividend will be paid, in CCYY-MM-DD format. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Date the dividend to be paid was declared, in CCYY-MM-DD format. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format. No definition available.
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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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