Stockholders' Equity of REIT and Partners' Capital of Operating Partnership - Additional Information (Detail) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Shareholders Equity [Line Items]
Third party ownership interest of common partnership units		0.38%
Public offering common shares		35,650,000
Share Price	$ 41.60	$ 41.60
Net proceeds fro public offering		$ 1,400,000,000
Maximum amount of equity distribution agreement amount	750,000,000	750,000,000
Equity distribution agents commission percentage	2.00%	2.00%
Redemption Premium Of Preferred Stock		9,108,000
Series Q Preferred Stock [Member]
Shareholders Equity [Line Items]
Redemption Premium Of Preferred Stock		$ 9,100,000
Preferred Stock Outstanding	2,000,000	2,000,000
Liquidation Preference Per share	$ 50	$ 50
Preferred Stock Par Value	$ 0.01	$ 0.01