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Stockholders' Equity and Mezzanine Equity - Summary of Changes in Stockholders' Equity (Detail) | 1 Months Ended | 12 Months Ended
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Feb. 29, 2012 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Series C Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) | 7.125% |  |  |
Ordinary Income [Member] | Common Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Common stock, dividend rate (as percent) |  | 28.81758% | 18.80114% | 0.00%
Ordinary Income [Member] | Senior Common Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Common stock, dividend rate (as percent) |  | 100.00% | 91.71368% | 0.00%
Ordinary Income [Member] | Series A Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 100.00% | 91.71368% | 24.10732%
Ordinary Income [Member] | Series B Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 100.00% | 91.71368% | 24.10732%
Ordinary Income [Member] | Series C Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 100.00% | 91.71368% | 24.10732%
Ordinary Income [Member] | Series D Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 100.00% | 0.00% | 0.00%
Return of Capital [Member] | Common Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Common stock, dividend rate (as percent) |  | 71.18242% | 79.50018% | 100.00%
Return of Capital [Member] | Senior Common Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Common stock, dividend rate (as percent) |  | 0.00% | 0.00% | 100.00%
Return of Capital [Member] | Series A Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 0.00% | 0.00% | 75.89268%
Return of Capital [Member] | Series B Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 0.00% | 0.00% | 75.89268%
Return of Capital [Member] | Series C Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 0.00% | 0.00% | 75.89268%
Return of Capital [Member] | Series D Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 0.00% | 0.00% | 0.00%
Long Term Capital Gains [Member] | Common Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Common stock, dividend rate (as percent) |  | 0.00% | 1.69868% | 0.00%
Long Term Capital Gains [Member] | Senior Common Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Common stock, dividend rate (as percent) |  | 0.00% | 8.28632% | 0.00%
Long Term Capital Gains [Member] | Series A Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 0.00% | 8.28632% | 0.00%
Long Term Capital Gains [Member] | Series B Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 0.00% | 8.28632% | 0.00%
Long Term Capital Gains [Member] | Series C Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 0.00% | 8.28632% | 0.00%
Long Term Capital Gains [Member] | Series D Preferred Stock [Member] |  |  |  |
Dividends Payable [Line Items] |  |  |  |
Preferred stock, dividend rate (as percent) |  | 0.00% | 0.00% | 0.00%

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