Condensed Consolidated Statement of Noncontrolling Interests and Equity - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Series A Preferred Operating Partnership [Member]	Series B Preferred Operating Partnership [Member]	Series C Preferred Operating Partnership [Member]	Series D Preferred Operating Partnership [Member]	Common Operating Partnership [Member]	Other [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]
Balance, beginning of period at Dec. 31, 2017	$ 2,723,807	$ 14,940	$ 41,902	$ 10,730	$ 92,064	$ 213,301	$ 119	$ 1,260	$ 2,569,485	$ 33,290	$ (253,284)
Balance, beginning of period (in shares) at Dec. 31, 2017	126,007,091							126,007,091
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon the exercise of options (in shares)								31,525
Issuance of common stock upon the exercise of options	$ 799								799
Restricted stock grants issued (in shares)								31,136
Restricted stock grants issued	0								0
Restricted stock grants canceled (in shares)								(770)
Restricted stock grants cancelled	0
Compensation expense related to stock-based awards	2,726								2,726
Repayment of receivable for preferred operating units pledged as collateral on loan	495			495
Redemption of Operating Partnership units for cash	(2,558)					(1,126)			(1,432)
Noncontrolling interest in consolidated joint venture	120						120
Repurchase of equity portion of 2013 exchangeable senior notes	(21,000)								(21,000)
Net income (loss)	95,430	1,156	629	676	929	3,784					88,256
Other comprehensive income	23,063	144				938				21,981
Distributions to Operating Partnership units held by noncontrolling interests	(7,909)	(1,254)	(629)	(676)	(929)	(4,421)
Dividends paid on common stock at $0.78 per share	(98,327)										(98,327)
Balance, end of period at Mar. 31, 2018	$ 2,716,646	$ 14,986	$ 41,902	$ 11,225	$ 92,064	$ 212,476	$ 239	$ 1,260	$ 2,550,578	$ 55,271	$ (263,355)
Balance, end of period (in shares) at Mar. 31, 2018	126,068,982							126,068,982