CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Preferred Shares Series C	Preferred Shares Series D	Preferred Shares Series E	Cumulative Preferred Distributions	Common Shares	Cumulative Common Distributions	Additional Paid in Capital	Cumulative Net Income	Cumulative Other Comprehensive Income (Loss)	Noncontrolling Interest in Consolidated Subsidiary
Balance at Dec. 31, 2010	$ 3,131,690	$ 145,015	$ 368,270		$ (432,252)	$ 721	$ (2,675,956)	$ 3,348,849	$ 2,372,337	$ 4,706
Balance (in shares) at Dec. 31, 2010		6,000,000	15,180,000			72,138,686
Comprehensive income (loss):
Net (loss) income	109,984								109,984
Unrealized gain (loss) on derivative instruments	(8,840)									(8,840)
Realized gain on sale of investment in available for sale securities	(19)									(19)
Foreign currency translation adjustments	(632)									(632)
Equity in unrealized income (loss) of an investee	76									76
Total comprehensive (loss) income	100,569
Issuance of shares, net	529,698			265,391		115		264,192
Issuance of shares, net (in shares)				11,000,000		11,500,000
Share grants	1,039					1		1,038
Share grants (in shares)						83,050
Distributions	(194,479)				(44,405)		(150,074)
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)
Balance (in shares) at Dec. 31, 2011		6,000,000	15,180,000	11,000,000		83,721,736
Comprehensive income (loss):
Net (loss) income	(79,845)								(95,421)		15,576
Unrealized gain (loss) on derivative instruments	(828)									(828)
Foreign currency translation adjustments	6,062									6,062
Equity in unrealized income (loss) of an investee	47									40	7
Total comprehensive (loss) income	(74,564)
Issuance of shares of subsidiary, net	363,657										363,657
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
Adjustments to noncontrolling interest resulting from changes in ownership of a subsidiary								(24,817)			24,817
Distributions	(207,635)				(52,710)		(146,539)				(8,386)
Balance at Dec. 31, 2012	3,501,468		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	83,804,068		15,180,000	11,000,000		83,804,068
Comprehensive income (loss):
Net (loss) income	(156,967)								(177,060)		20,093
Unrealized gain (loss) on derivative instruments	4,918									4,918
Foreign currency translation adjustments	(43,718)									(43,718)
Equity in unrealized income (loss) of an investee	(132)									(96)	(36)
Total comprehensive (loss) income	(195,899)
Issuance of shares, net	626,809					345		626,506			(42)
Issuance of shares, net (in shares)						34,500,000
Share grants	1,821					1		1,536			284
Share grants (in shares)						82,850
Adjustments to noncontrolling interest resulting from changes in ownership of a subsidiary								32			(32)
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		$ 368,270	$ 265,391	$ (573,971)	$ 1,184	$ (3,082,271)	$ 4,213,474	$ 2,209,840	$ (38,331)
Balance (in shares) at Dec. 31, 2013	118,386,918		15,180,000	11,000,000		118,386,918