Consolidated Statement of Changes in Stockholders' Equity and Noncontrolling Interests (Unaudited) - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Noncontrolling Interests	Redeemable Noncontrolling Interests	Series D Cumulative Convertible Preferred Stock Preferred Stock	Series D Cumulative Convertible Preferred Stock Additional Paid-In Capital	Series E Cumulative Redeemable Preferred Stock Preferred Stock
Beginning balance (shares) at Dec. 31, 2015		72,548,693
Beginning balance at Dec. 31, 2015	$ 4,279,746	$ 725	$ 3,558,008	$ 0	$ 49,191	$ 304,659		$ 237,163		$ 130,000
Increase (Decrease) in Stockholders' Equity
Net Income	(98,745)			(105,680)		6,935
Total other comprehensive loss	(40,943)				(40,919)	(24)
Distributions to noncontrolling interests	(5,970)					(5,970)
Issuances of common stock (shares)		3,948,491
Issuances of common stock	367,802	$ 40	367,762
Issuances pursuant to stock plan (in shares)		118,012
Issuances pursuant to stock plan	17,801	$ 1	17,800
Noncontrolling Interest, Increase from Sale of Parent Equity Interest						30,950
Repurchase of Series D preferred stock	(59,310)			(12,519)				(48,299)	$ 1,508
Dividends declared on common stock	(121,477)			(121,477)
Dividends on preferred stock	(11,381)			(11,381)
Distributions in excess of earnings			(251,057)	251,057
Ending balance (shares) at Jun. 30, 2016		76,615,196
Ending balance at Jun. 30, 2016	4,358,259	$ 766	$ 3,693,807	$ 0	$ 8,272	$ 336,550		$ 188,864		$ 130,000
Beginning balance at Dec. 31, 2015	14,218						$ 14,218
Increase (Decrease) in Temporary Equity [Roll Forward]
Net Income							595
Total other comprehensive loss							0
Repurchase of redeemable noncontrolling interests							(5,000)
Distributions to noncontrolling interests							(595)
Ending balance at Jun. 30, 2016	$ 9,218						$ 9,218