Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Dividends Paid (Detail)

v3.4.0.3
Stockholders' Equity - Dividends Paid (Detail) - $ / shares
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Common Stock [Member]    
Dividends Payable [Line Items]    
Common Stock, dividends paid per share $ 0.375 $ 0.375
Senior Common Stock [Member]    
Dividends Payable [Line Items]    
Common Stock, dividends paid per share 0.2625 0.2625
Series A Preferred Stock [Member]    
Dividends Payable [Line Items]    
Preferred Stock, dividends paid per share 0.4843749 0.4843749
Series B Preferred Stock [Member]    
Dividends Payable [Line Items]    
Preferred Stock, dividends paid per share 0.4688 0.4688
Series C Preferred Stock [Member]    
Dividends Payable [Line Items]    
Preferred Stock, dividends paid per share $ 0.4453 $ 0.4453