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Stockholders' and Mezzanine Equity - Dividends Paid (Detail) - $ / shares | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016
Common Stock |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Common Stock, dividends paid per share | $ 0.375 | $ 0.375 | $ 1.125 | $ 1.125
Senior Common Stock |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Common Stock, dividends paid per share | 0.2625 | 0.2625 | 0.7875 | 0.7875
Series A Preferred Stock |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred Stock, dividends paid per share | 0.4843749 | 0.4843749 | 1.4531247 | 1.4531247
Series B Preferred Stock |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred Stock, dividends paid per share | 0.4688 | 0.4688 | 1.4063 | 1.4063
Series C Preferred Stock |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred Stock, dividends paid per share | 0 | 0.2424 | 0.0000 | 1.1330
Series D Preferred Stock |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred Stock, dividends paid per share | $ 0.4375 | $ 0.4375 | $ 1.3125 | $ 0.6163

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- Definition Aggregate dividends paid during the period for each share of common stock outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
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