Stockholders' Equity - Summary of Dividend Distributions (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Class of Stock [Line Items]
Total Common Dividend/ Distribution	$ 35,416
Total Preferred Dividend/ Distribution	1,019
Common Stock/Operating Partnership Units
Class of Stock [Line Items]
Total Common Dividend/ Distribution	35,416
Series F Preferred Stock
Class of Stock [Line Items]
Total Preferred Dividend/ Distribution	566
Series G Preferred Stock
Class of Stock [Line Items]
Total Preferred Dividend/ Distribution	$ 453