Stockholders’ Equity of the Company and Partners' Capital of the Operating Partnership - Summary of Dividends/Distributions (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Class of Stock [Line Items]
Total Common Stock Dividend / Unit Distribution		$ 59,014	$ 47,263		$ 38,862
Total Preferred Dividend / Distribution			1,019		8,733
Common Stock / Operating Partnership Units
Class of Stock [Line Items]
Total Common Stock Dividend / Unit Distribution		$ 59,014	47,263		38,862
Series F Preferred Stock/Units
Class of Stock [Line Items]
Total Preferred Dividend / Distribution			566	[1]	2,896
Series G Preferred Stock/Units
Class of Stock [Line Items]
Total Preferred Dividend / Distribution			$ 453	[1]	1,809
Series J Preferred Stock/Units
Class of Stock [Line Items]
Total Preferred Dividend / Distribution	[1]				2,034
Series K Preferred Stock/Units
Class of Stock [Line Items]
Total Preferred Dividend / Distribution	[1]				$ 1,994

[1] See the "Preferred Stock/Contributions" section for the redemptions and discussion of pro-rated dividends/distributions for all series of preferred stock/Units occurring during the years ended December 31, 2014 and 2013.