CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Series C	Series D	Series E	Cumulative Preferred Distributions	Common Stock	Cumulative Common Distributions	Additional Paid in Capital	Cumulative Net Income	Cumulative Other Comprehensive Income (Loss)	Noncontrolling Interest in Consolidated Subsidiary
Balance at Dec. 31, 2011	$ 3,568,517	$ 145,015	$ 368,270	$ 265,391	$ (476,657)	$ 837	$ (2,826,030)	$ 3,614,079	$ 2,482,321	$ (4,709)	$ 0
Balance (in shares) at Dec. 31, 2011		6,000,000	15,180,000	11,000,000		83,721,736
Comprehensive income (loss):
Net income (loss)	(79,845)								(95,421)		15,576
Unrealized gain (loss) on derivative instruments and other assets	(828)									(828)
Foreign currency translation adjustments	6,062									6,062
Equity in unrealized income of an investee	47									40	7
Total comprehensive income (loss)	(74,564)
Issuance of shares of subsidiary, net	363,657										363,657
Adjustments to noncontrolling interest from changes in ownership of a subsidiary	0							(24,817)			24,817
Redemption of shares	(150,000)	(145,015)						(4,985)
Redemption of shares (in shares)		(6,000,000)
Share grants	1,493					1		1,123			369
Share grants (in shares)						82,332
Distributions	(207,635)				(52,710)		(146,539)				(8,386)
Balance at Dec. 31, 2012	3,501,468	0	368,270	265,391	(529,367)	838	(2,972,569)	3,585,400	2,386,900	565	396,040
Balance (in shares) at Dec. 31, 2012		0	15,180,000	11,000,000		83,804,068
Comprehensive income (loss):
Net income (loss)	(156,967)								(177,060)		20,093
Unrealized gain (loss) on derivative instruments and other assets	4,918									4,918
Foreign currency translation adjustments	(43,718)									(43,718)
Equity in unrealized income of an investee	(132)									(96)	(36)
Total comprehensive income (loss)	(195,899)
Issuance of shares, net	626,809					345		626,506			(42)
Issuance of shares, net (in shares)						34,500,000
Adjustments to noncontrolling interest from changes in ownership of a subsidiary	0							32			(32)
Share grants	1,821					1		1,536			284
Share grants (in shares)						82,850
Distributions	(169,169)				(44,604)		(109,702)				(14,863)
Deconsolidation of a subsidiary	(401,444)										(401,444)
Balance at Dec. 31, 2013	3,363,586	0	368,270	265,391	(573,971)	1,184	(3,082,271)	4,213,474	2,209,840	(38,331)	0
Balance (in shares) at Dec. 31, 2013	118,386,918	0	15,180,000	11,000,000		118,386,918
Comprehensive income (loss):
Net income (loss)	24,012								24,012
Unrealized gain (loss) on derivative instruments and other assets	7,407									7,407
Foreign currency translation adjustments	(22,270)									(22,270)
Equity in unrealized income of an investee	(22)									(22)
Total comprehensive income (loss)	9,127
Issuance of shares, net	2,402							2,402
Issuance of shares, net (in shares)						90,135
Redemption of shares	0		(249,004)		(16,205)	104		265,105
Redemption of shares (in shares)			(10,264,503)			10,412,499
Share grants	6,160					8		6,152
Share grants (in shares)						717,727
Distributions	(61,692)				(32,095)		(29,597)
Balance at Dec. 31, 2014	$ 3,319,583	$ 0	$ 119,266	$ 265,391	$ (622,271)	$ 1,296	$ (3,111,868)	$ 4,487,133	$ 2,233,852	$ (53,216)	$ 0
Balance (in shares) at Dec. 31, 2014	129,607,279	0	4,915,497	11,000,000		129,607,279