Stockholders' Equity - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended			3 Months Ended			3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 Series F Preferred Stock	Mar. 06, 2014 Series F Preferred Stock	Mar. 31, 2014 Series F Preferred Stock Minimum	Mar. 31, 2014 Series G Preferred Stock	Mar. 31, 2014 Convertible Common Stock
Class of Stock [Line Items]
Depositary shares redeemed					50,000		25,000
Depositary share percentage per share					$ 0.01		$ 0.01
Dividend rate per share				6.236%			7.236%
Preferred stock, par value per share					$ 0.01		$ 0.01
Redemption price per share					$ 1,000.00		$ 1,000.00
Dividend per share				$ 11.3299			$ 36.18
Total dividend				$ 566			$ 905
Cost associated with share redemption	1,462	0
Preferred stock shares authorized	10,000,000
Preferred stock, shares outstanding	0		750
Fixed coupon rate of preferred stock						2.375%
Number of years of US treasury rate one				30 years
Number of years of US treasury rate two				10 years
LIBOR rate				3-month LIBOR
New coupon rate of preferred stock				6.275%
Units converted into common stock								131,844
Noncontrolling interest reclassified to stockholders' equity	$ 0	$ 0						$ 1,279