Stockholders' Equity of REIT and Partners' Capital of Operating Partnership - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended		3 Months Ended
	Apr. 30, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013 Series Q Preferred Stock [Member]	Sep. 30, 2013 Series Q Preferred Stock [Member]
Shareholders Equity [Line Items]
Third party ownership interest of common partnership units		0.37%
Public offering common shares	35,650,000
Share Price	$ 41.60
Net proceeds fro public offering	$ 1,400,000,000
Maximum amount of equity distribution agreement amount			750,000,000
Equity distribution agents commission percentage			2.00%
Redemption Premium of Preferred Stock		$ 9,108,000		$ 9,100,000
Preferred Stock Outstanding					2,000,000
Liquidation Preference Per share					$ 50
Preferred Stock Par Value					$ 0.01