Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total
Balance at Dec. 31, 2016	$ (676,867)	$ 5,766	$ 32	$ 4,250	$ 5,922,958	$ 5,256,139	$ 146,735	$ 5,402,874
Balance (in shares) at Dec. 31, 2016			32,000	425,034,000
Contributions/deemed contributions from noncontrolling interests	0	0	$ 0	$ 0	0	0	48,877	48,877
Net income	426,075	0	0	0	0	426,075	13,596	439,671
Change in unrealized gains/losses related to available-for-sale securities	0	(1,542)	0	0	0	(1,542)	0	(1,542)
Change in unrealized value on interest rate swaps	0	631	0	0	0	631	0	631
Change in foreign currency translation adjustments	0	(6,335)	0	0	0	(6,335)	0	(6,335)
Redeemable noncontrolling interests income	0	0	0	0	0	0	(1,297)	(1,297)
Dividends declared to common and preferred shares	(510,545)	0	0	0	0	(510,545)	0	(510,545)
Distributions to noncontrolling interests	0	0	0	0	0	0	(13,995)	(13,995)
Issuance of common stock	0	0	$ 0	$ 8	(8)	0	0	0
Issuance of common stock (in shares)			0	776,000
Issuance of preferred stock	0	0	$ 18	$ 0	439,401	439,419	0	439,419
Issuance of preferred stock (in shares)			18,000	0
Surrender of restricted stock	0	0	$ 0	$ (2)	(5,697)	(5,699)	0	(5,699)
Surrender of restricted stock (in shares)			0	(248,000)
Exercise of common stock options	0	0	$ 0	$ 0	1,526	1,526	0	$ 1,526
Exercise of common stock options (in shares)			0	84,000				83,863
Amortization of equity awards	0	0	$ 0	$ 0	18,983	18,983	0	$ 18,983
Redemption of preferred stock	0	0	$ (9)	$ 0	(224,991)	(225,000)	0	$ (225,000)
Redemption of preferred stock (in shares)			(9,000)	0
Repurchase of common stock (in shares)								(232,304)
Balance at Dec. 31, 2017	(761,337)	(1,480)	$ 41	$ 4,256	6,152,764	5,394,244	127,903	$ 5,522,147
Balance (in shares) at Dec. 31, 2017			41,000	425,646,000
Redemption/conversion of noncontrolling interests | Accounting Standards Update 2017-05 [Member]	8,098	0	$ 0	$ 0	0	8,098	0	8,098
Redemption/conversion of noncontrolling interests | Accounting Standards Update 2016-01 [Member]	(1,136)	1,136	0	0	0	0	0	0
Redemption/conversion of noncontrolling interests	0	0	0	0	592	592	(66,013)	(65,421)
Contributions/deemed contributions from noncontrolling interests	0	0	0	0	0	0	109	109
Net income	497,795	0	0	0	0	497,795	668	498,463
Change in unrealized gains/losses related to available-for-sale securities								0
Change in unrealized value on interest rate swaps	0	344	0	0	0	344	0	344
Change in foreign currency translation adjustments								0
Redeemable noncontrolling interests income	0	0	0	0	0	0	(373)	(373)
Dividends declared to common and preferred shares	(531,127)	0	0	0	0	(531,127)	0	(531,127)
Distributions to noncontrolling interests	0	0	0	0	0	0	(2,663)	(2,663)
Issuance of common stock	0	0	$ 0	$ 11	(11)	0	0	0
Issuance of common stock (in shares)			0	1,101,000
Issuance of preferred stock	0	0	$ 2	$ 0	33,112	33,114	0	33,114
Issuance of preferred stock (in shares)			2,000	0
Surrender of restricted stock	0	0	$ 0	$ (3)	(4,357)	(4,360)	0	(4,360)
Surrender of restricted stock (in shares)			0	(300,000)
Exercise of common stock options	0	0	$ 0	$ 1	591	592	0	$ 592
Exercise of common stock options (in shares)			0	42,000				42,259
Amortization of equity awards	0	0	$ 0	$ 0	16,548	16,548	0	$ 16,548
Redemption/conversion of noncontrolling interests | Accounting Standards Update 2017-05 [Member]	8,098	0	0	0	0	8,098	0	8,098
Redemption/conversion of noncontrolling interests | Accounting Standards Update 2016-01 [Member]	(1,136)	1,136	0	0	0	0	0	0
Redemption/conversion of noncontrolling interests	0	0	0	0	592	592	(66,013)	(65,421)
Impact of change in accounting principles (Accounting Standards Update 2017-05 [Member]) at Dec. 31, 2017	8,098	0	0	0	0	8,098	0	8,098
Impact of change in accounting principles (Accounting Standards Update 2016-01 [Member]) at Dec. 31, 2017	(1,136)	1,136	0	0	0	0	0	0
Impact of change in accounting principles at Dec. 31, 2017	0	0	0	0	592	592	(66,013)	(65,421)
Balance at Dec. 31, 2017	(754,375)	(344)	41	4,256	6,152,764	5,402,342	127,903	5,530,245
Repurchase of common stock	0	0	$ 0	$ (51)	(75,075)	(75,126)	0	$ (75,126)
Repurchase of common stock (in shares)			0	(5,100,000)				(278,566)
Acquisition/deconsolidation of noncontrolling interests	0	0	$ 0	$ 0	1,203	1,203	(48,395)	$ (47,192)
Adjustment of redeemable noncontrolling interests to estimated fair value	0	0	0	0	(7,521)	(7,521)	0	(7,521)
Balance at Dec. 31, 2018	(787,707)	0	$ 43	$ 4,214	6,117,254	5,333,804	77,249	5,411,053
Balance (in shares) at Dec. 31, 2018			43,000	421,389,000
Net income	410,605	0	$ 0	$ 0	0	410,605	2,956	413,561
Change in unrealized gains/losses related to available-for-sale securities								0
Change in unrealized value on interest rate swaps								0
Change in foreign currency translation adjustments								0
Redeemable noncontrolling interests income	0	0	0	0	0	0	(358)	(358)
Dividends declared to common and preferred shares	(527,577)	0	0	0	0	(527,577)	0	(527,577)
Distributions to noncontrolling interests	0	0	0	0	0	0	(10,638)	(10,638)
Issuance of common stock	0	0	$ 0	$ 105	200,028	200,133	0	200,133
Issuance of common stock (in shares)			0	10,398,000
Surrender of restricted stock	0	0	$ 0	$ (3)	(4,027)	(4,030)	0	(4,030)
Surrender of restricted stock (in shares)			0	(242,000)
Exercise of common stock options	0	0	$ 0	$ 2	3,878	3,880	0	$ 3,880
Exercise of common stock options (in shares)			0	269,000				268,856
Amortization of equity awards	0	0	$ 0	$ 0	19,083	19,083	0	$ 19,083
Redemption of preferred stock	0	0	$ (23)	$ 0	(574,977)	(575,000)	0	$ (575,000)
Redemption of preferred stock (in shares)			(23,000)	0
Repurchase of common stock (in shares)								(223,609)
Acquisition/deconsolidation of noncontrolling interests	0	0	$ 0	$ 0	3,994	3,994	(5,194)	$ (1,200)
Balance at Dec. 31, 2019	$ (904,679)	$ 0	$ 20	$ 4,318	$ 5,765,233	$ 4,864,892	$ 64,015	$ 4,928,907
Balance (in shares) at Dec. 31, 2019			20,000	431,814,000