CONSOLIDATED STATEMENT OF EQUITY - USD ($) $ in Thousands	Total	Preferred Shares [Member]	Common Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Distributions in Excess of Net Income [Member]	Deferred Compensation Obligation [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock at Cost [Member]	Non-Controlling Interests [Member]
Balance at Dec. 31, 2017	$ 2,897,438	$ 525,000	$ 18,426	$ 5,531,249	$ (3,183,134)	$ 8,777	$ (1,106)	$ (8,280)	$ 6,506
Issuance of common shares related to stock plans	5,930	0	39	5,891	0	0	0	0	0
Stock-based compensation, net	4,903	0	0	4,986	0	(1,059)	0	976	0
Distributions to non-controlling interests	(837)	0	0	0	0	0	0	0	(837)
Redemption of OP Units	(709)	0	0	880	0	0	0	0	(1,589)
Dividends declared-common shares	(140,611)	0	0	0	(140,611)	0	0	0	0
Dividends declared-preferred shares	(16,766)	0	0	0	(16,766)	0	0	0	0
Comprehensive (loss) income	(57,010)	0	0	0	(57,482)	0	(351)	0	823
Balance at Jun. 30, 2018	2,692,338	525,000	18,465	5,543,006	(3,397,993)	7,718	(1,457)	(7,304)	4,903
Balance at Dec. 31, 2017	2,897,438	525,000	18,426	5,531,249	(3,183,134)	8,777	(1,106)	(8,280)	6,506
Comprehensive (loss) income	(65,283)
Balance at Sep. 30, 2018	1,974,991	525,000	18,467	5,542,949	(4,115,736)	8,474	(1,093)	(8,054)	4,984
Balance at Jun. 30, 2018	2,692,338	525,000	18,465	5,543,006	(3,397,993)	7,718	(1,457)	(7,304)	4,903
Issuance of common shares related to stock plans	39	0	2	37	0	0	0	0	0
Stock-based compensation, net	(88)	0	0	(94)	0	756	0	(750)	0
Distributions to non-controlling interests	(213)	0	0	0	0	0	0	0	(213)
Dividends declared-common shares	(37,024)	0	0	0	(37,024)	0	0	0	0
Dividends declared-preferred shares	(8,382)	0	0	0	(8,382)	0	0	0	0
RVI spin-off	(663,406)	0	0	0	(663,406)	0	0	0	0
Comprehensive (loss) income	(8,273)	0	0	0	(8,931)	0	364	0	294
Balance at Sep. 30, 2018	1,974,991	525,000	18,467	5,542,949	(4,115,736)	8,474	(1,093)	(8,054)	4,984
Balance at Dec. 31, 2018	2,073,002	525,000	18,471	5,544,220	(3,980,151)	8,193	(1,381)	(44,278)	2,928
Issuance of common shares related to stock plans	0	0	1	(1)	0	0	0	0	0
Repurchase of common shares	(14,069)	0	0	0	0	0	0	(14,069)	0
Stock-based compensation, net	3,729	0	0	2,188	0	(147)	0	1,688	0
Distributions to non-controlling interests	(379)	0	0	0	0	0	0	0	(379)
Dividends declared-common shares	(72,510)	0	0	0	(72,510)	0	0	0	0
Dividends declared-preferred shares	(16,766)	0	0	0	(16,766)	0	0	0	0
Comprehensive (loss) income	54,244	0	0	0	53,067	0	612	0	565
Balance at Jun. 30, 2019	2,027,251	525,000	18,472	5,546,407	(4,016,360)	8,046	(769)	(56,659)	3,114
Balance at Dec. 31, 2018	2,073,002	525,000	18,471	5,544,220	(3,980,151)	8,193	(1,381)	(44,278)	2,928
Comprehensive (loss) income	78,157
Balance at Sep. 30, 2019	2,007,505	525,000	18,472	5,547,534	(4,037,373)	8,070	(757)	(56,520)	3,079
Balance at Jun. 30, 2019	2,027,251	525,000	18,472	5,546,407	(4,016,360)	8,046	(769)	(56,659)	3,114
Issuance of common shares related to stock plans	21	0	0	21	0	0	0	0	0
Stock-based compensation, net	1,269	0	0	1,106	0	24	0	139	0
Distributions to non-controlling interests	(306)	0	0	0	0	0	0	0	(306)
Dividends declared-common shares	(36,261)	0	0	0	(36,261)	0	0	0	0
Dividends declared-preferred shares	(8,382)	0	0	0	(8,382)	0	0	0	0
Comprehensive (loss) income	23,913	0	0	0	23,630	0	12	0	271
Balance at Sep. 30, 2019	$ 2,007,505	$ 525,000	$ 18,472	$ 5,547,534	$ (4,037,373)	$ 8,070	$ (757)	$ (56,520)	$ 3,079