Condensed Consolidated Statement of Equity (Unaudited) Statement - 6 months ended Jun. 30, 2017 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Cumulative Net Income Attributable to Common Stockholders	Cumulative Dividends
Beginning balance at Dec. 31, 2016	$ 1,653,414	$ 1,164	$ 2,917,914	$ (1,401)	$ 995,256	$ (2,259,519)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock	1,041		1,041
Common stock redemptions	(502)		(502)
Stock-based compensation	5,067	1	5,066
Net income	57,070				57,070
Reclassification of loss on forward starting interest rate swaps	85			85
Dividends to common stockholders ($0.60 per share)	(69,898)					(69,898)
Ending balance at Jun. 30, 2017	$ 1,646,277	$ 1,165	$ 2,923,519	$ (1,316)	$ 1,052,326	$ (2,329,417)