Condensed Consolidated Statement of Equity - 9 months ended Sep. 30, 2016 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Distributions in Excess of Accumulated Earnings [Member]	Accumulated Other Comprehensive Loss, Net [Member]	Noncontrolling Interest [Member]	Series H Preferred Stock [Member]
Balance at period beginning at Dec. 31, 2015	$ 6,337,023	$ 6	$ 7,003,317	$ (797,329)	$ (42,011)	$ 99,290	$ 73,750
Balances (in shares) at Dec. 31, 2015		65,379					2,950
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	233,893			219,410		14,483
Change in fair value of derivatives and amortization of swap settlements	3,481				3,367	114
Change in fair value of marketable securities, net	(1,500)				(1,451)	(49)
Issuance of common stock under:
Stock option and restricted stock plans, net	17,878		17,878
Stock option and restricted stock plans, net (in shares)		130
Sale of common stock, net	(382)		(382)
Equity based compensation costs	4,436		2,662			1,774
Redemption of Series H preferred stock	(73,750)		2,541	(2,541)			$ (73,750)
Redemption of Series H preferred stock (in shares)							(2,950)
Changes in the redemption value of redeemable noncontrolling interest	1,343		785			558
Distributions to noncontrolling interest	(20,425)					(20,425)
Redemptions of noncontrolling interest	(2,435)		(1,974)			(461)
Redemptions of noncontrolling interest (in shares)		14
Common and preferred stock dividends	(315,660)			(315,660)
Balance at period end at Sep. 30, 2016	$ 6,183,902	$ 6	$ 7,024,827	$ (896,120)	$ (40,095)	$ 95,284	$ 0
Balances (in shares) at Sep. 30, 2016		65,523					0