Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Dividends Declared (Detail)

v3.3.1.900
Stockholders' Equity - Dividends Declared (Detail) - $ / shares
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Common Stock [Member]      
Dividends Payable [Line Items]      
Common Stock, distributions declared per share $ 1.50 $ 1.50 $ 1.50
Senior Common Stock [Member]      
Dividends Payable [Line Items]      
Common Stock, distributions declared per share 1.05 1.05 1.05
Series A Preferred Stock [Member]      
Dividends Payable [Line Items]      
Preferred Stock, distributions declared per share 1.9374996 1.9374996 1.9374996
Series B Preferred Stock [Member]      
Dividends Payable [Line Items]      
Preferred Stock, distributions declared per share 1.8750 1.8750 1.8750
Series C Preferred Stock [Member]      
Dividends Payable [Line Items]      
Preferred Stock, distributions declared per share $ 1.7813 $ 1.7813 $ 1.7813