Stockholders' Equity of the REIT - Schedule of Preferred Stock (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]
Total preferred stock	$ 100,000	$ 582,200
Series L Preferred Stock [Member]
Class of Stock [Line Items]
Total preferred stock		49,100
Series M Preferred Stock [Member]
Class of Stock [Line Items]
Total preferred stock		57,500
Series O Preferred Stock [Member]
Class of Stock [Line Items]
Total preferred stock		75,300
Series P Preferred Stock [Member]
Class of Stock [Line Items]
Total preferred stock		50,300
Series Q Preferred Stock [Member]
Class of Stock [Line Items]
Total preferred stock	100,000	100,000
Series R Preferred Stock [Member]
Class of Stock [Line Items]
Total preferred stock		125,000
Series S Preferred Stock [Member]
Class of Stock [Line Items]
Total preferred stock		$ 125,000