Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity and Mezzanine Equity - Summary of Changes in Stockholders' Equity (Detail)

v3.6.0.2
Stockholders' Equity and Mezzanine Equity - Summary of Changes in Stockholders' Equity (Detail)
 1 Months Ended 12 Months Ended
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%