Consolidated Statement of Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In-Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Retained Earnings	Noncontrolling Interests	Series I Preferred Stock Preferred Stock	Cumulative Effect, Period Of Adoption, Adjustment	Cumulative Effect, Period Of Adoption, Adjustment Retained Earnings	Cumulative Effect, Period Of Adoption, Adjusted Balance	Cumulative Effect, Period Of Adoption, Adjusted Balance Common Stock	Cumulative Effect, Period Of Adoption, Adjusted Balance Additional Paid-In-Capital	Cumulative Effect, Period Of Adoption, Adjusted Balance Treasury Stock	Cumulative Effect, Period Of Adoption, Adjusted Balance Accumulated Other Comprehensive Loss	Cumulative Effect, Period Of Adoption, Adjusted Balance Retained Earnings	Cumulative Effect, Period Of Adoption, Adjusted Balance Noncontrolling Interests	Cumulative Effect, Period Of Adoption, Adjusted Balance Series I Preferred Stock Preferred Stock
Beginning Balance at Dec. 31, 2018	$ 5,947,855	$ 847	$ 4,508,685	$ (124,049)	$ 15,108	$ 1,278,998	$ 46,334	$ 221,932
Beginning Balance (in shares) at Dec. 31, 2018		83,684
Increase (Decrease) in Stockholders' Equity
Net income (loss)	47,767					47,530	237
Other comprehensive loss	(19,113)				(19,113)
Preferred dividends	(3,738)					(3,738)
DRSPP proceeds (in shares)		1
DRSPP proceeds	47		47
Conversion of units of the Operating Partnership to common stock (in shares)		5
Conversion of units in the Operating Partnership for common stock	446		446
Reallocation of noncontrolling interest in the Operating Partnership	(28,932)					(28,932)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)		(20)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	4,835		4,835
Repurchases of common stock (in shares)		(398)
Repurchases of common stock	(34,243)	$ (4)	(21,432)			12,807
Contributions to consolidated joint venture interests	161						161
Cash distributions to noncontrolling interests	(208)						(208)
Cash distributions declared (per common share, none of which represented a return of capital for federal income tax purposes)	(70,554)					(70,554)
Ending Balance at Mar. 31, 2019	5,844,323	$ 843	4,492,581	(124,049)	(4,005)	1,210,497	46,524	221,932
Ending Balance (in shares) at Mar. 31, 2019		83,272
Beginning Balance at Dec. 31, 2018	5,947,855	$ 847	4,508,685	(124,049)	15,108	1,278,998	46,334	221,932
Beginning Balance (in shares) at Dec. 31, 2018		83,684
Increase (Decrease) in Stockholders' Equity
Preferred dividends	(7,475)
Ending Balance at Jun. 30, 2019	5,879,501	$ 835	4,451,209	(124,049)	(28,395)	1,288,390	69,579	221,932
Ending Balance (in shares) at Jun. 30, 2019		82,410
Beginning Balance at Dec. 31, 2018	5,947,855	$ 847	4,508,685	(124,049)	15,108	1,278,998	46,334	221,932
Beginning Balance (in shares) at Dec. 31, 2018		83,684
Ending Balance at Dec. 31, 2019	5,517,198	$ 803	4,286,395	(124,049)	(28,485)	1,084,719	75,883	221,932			$ 5,478,014	$ 803	$ 4,286,395	$ (124,049)	$ (28,485)	$ 1,045,535	$ 75,883	$ 221,932
Ending Balance (Accounting Standards Update 2016-13) at Dec. 31, 2019									$ (39,184)	$ (39,184)
Ending Balance (in shares) at Dec. 31, 2019		79,202										79,202
Beginning Balance at Mar. 31, 2019	5,844,323	$ 843	4,492,581	(124,049)	(4,005)	1,210,497	46,524	221,932
Beginning Balance (in shares) at Mar. 31, 2019		83,272
Increase (Decrease) in Stockholders' Equity
Net income (loss)	162,702					164,840	(2,138)
Acquisition of subsidiary interest from noncontrolling interest	(25,791)		(515)				(25,276)
Other comprehensive loss	(24,390)				(24,390)
Preferred dividends	(3,737)					(3,737)
DRSPP proceeds (in shares)		2
DRSPP proceeds	216		216
Reallocation of noncontrolling interest in the Operating Partnership	14,904					14,904
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)		3
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	5,698		5,698
Repurchases of common stock (in shares)		(867)
Repurchases of common stock	(75,070)	$ (8)	(46,771)			28,291
Contributions to consolidated joint venture interests	50,532						50,532
Cash distributions to noncontrolling interests	(63)						(63)
Cash distributions declared (per common share, none of which represented a return of capital for federal income tax purposes)	(69,823)					(69,823)
Ending Balance at Jun. 30, 2019	5,879,501	$ 835	4,451,209	(124,049)	(28,395)	1,288,390	69,579	221,932
Ending Balance (in shares) at Jun. 30, 2019		82,410
Beginning Balance at Dec. 31, 2019	5,517,198	$ 803	4,286,395	(124,049)	(28,485)	1,084,719	75,883	221,932			5,478,014	$ 803	4,286,395	(124,049)	(28,485)	1,045,535	75,883	221,932
Beginning Balance (in shares) at Dec. 31, 2019		79,202										79,202
Increase (Decrease) in Stockholders' Equity
Net income (loss)	118,246					118,539	(293)
Acquisition of subsidiary interest from noncontrolling interest	(1,536)		(3,123)				1,587
Other comprehensive loss	(52,383)				(52,383)
Preferred dividends	(3,738)					(3,738)
DRSPP proceeds (in shares)		2
DRSPP proceeds	166		166
Conversion of units of the Operating Partnership to common stock (in shares)		1
Conversion of units in the Operating Partnership for common stock	84		84
Reallocation of noncontrolling interest in the Operating Partnership	38,529					38,529
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)		(33)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	5,502	$ (1)	5,503
Repurchases of common stock (in shares)		(2,637)
Repurchases of common stock	(219,576)	$ (26)	(142,719)			(76,831)
Contributions to consolidated joint venture interests	3,814						3,814
Cash distributions to noncontrolling interests	(492)						(492)
Cash distributions declared (per common share, none of which represented a return of capital for federal income tax purposes)	(22,665)					(22,665)
Ending Balance at Mar. 31, 2020	5,343,965	$ 776	4,146,306	(124,049)	(80,868)	1,099,369	80,499	221,932
Ending Balance (in shares) at Mar. 31, 2020		76,535
Beginning Balance at Dec. 31, 2019	5,517,198	$ 803	4,286,395	(124,049)	(28,485)	1,084,719	75,883	221,932			$ 5,478,014	$ 803	$ 4,286,395	$ (124,049)	$ (28,485)	$ 1,045,535	$ 75,883	$ 221,932
Beginning Balance (Accounting Standards Update 2016-13) at Dec. 31, 2019									$ (39,184)	$ (39,184)
Beginning Balance (in shares) at Dec. 31, 2019		79,202										79,202
Increase (Decrease) in Stockholders' Equity
Preferred dividends	(7,475)
Ending Balance at Jun. 30, 2020	5,205,762	$ 748	4,021,891	(124,049)	(82,371)	1,081,821	85,790	221,932
Ending Balance (in shares) at Jun. 30, 2020		73,675
Beginning Balance at Mar. 31, 2020	5,343,965	$ 776	4,146,306	(124,049)	(80,868)	1,099,369	80,499	221,932
Beginning Balance (in shares) at Mar. 31, 2020		76,535
Increase (Decrease) in Stockholders' Equity
Net income (loss)	61,204					60,181	1,023
Acquisition of subsidiary interest from noncontrolling interest	0
Other comprehensive loss	(1,503)				(1,503)
Preferred dividends	(3,737)					(3,737)
DRSPP proceeds (in shares)		4
DRSPP proceeds	198		198
Conversion of units of the Operating Partnership to common stock (in shares)		100
Conversion of units in the Operating Partnership for common stock	8,660	$ 1	8,659
Reallocation of noncontrolling interest in the Operating Partnership	(7,385)					(7,385)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	7,991	$ 1	7,990
Repurchases of common stock (in shares)		(2,964)
Repurchases of common stock	(141,292)	$ (30)	(141,262)
Contributions to consolidated joint venture interests	4,372						4,372
Cash distributions to noncontrolling interests	(104)						(104)
Cash distributions declared (per common share, none of which represented a return of capital for federal income tax purposes)	(66,607)					(66,607)
Ending Balance at Jun. 30, 2020	$ 5,205,762	$ 748	$ 4,021,891	$ (124,049)	$ (82,371)	$ 1,081,821	$ 85,790	$ 221,932
Ending Balance (in shares) at Jun. 30, 2020		73,675