Consolidated Statements Of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Preferred Stock [Member]	Additional Paid-In Capital [Member]	Dividends In Excess Of Earnings [Member]	Treasury Stock, At Cost [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
Equity, value at Dec. 31, 2013	$ 7,043,618	$ 1,530		$ 5,662,453	$ (108,552)	$ (2,722)	$ (11,556)	$ 1,302,465
Equity, shares at Dec. 31, 2013		152,983,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of operating partnership units to Common Stock, shares		80,000
Conversion of operating partnership units to Common Stock, value	0	$ 1		2,699				(2,700)
Conversion of redeemable preferred units to common units	33,306							33,306
Allocated net income for the year	513,951				443,611			70,340
Dividends/distributions declared	(1,224,471)				(1,097,523)			(126,948)
Shares issued in connection with exchange of exchangeable senior notes, value		$ 0
Shares issued pursuant to stock purchase plan, shares		7,000
Shares issued pursuant to stock purchase plan, value	761			761
Net activity from stock option and incentive plan, shares		44,000
Net activity from stock option and incentive plan, value	27,999			6,822				21,177
Sale of interest in property partnerships and contributions from noncontrolling interest in property partnerships	1,536,382			648,407				887,975
Distributions to noncontrolling interests in property partnerships	(31,118)							(31,118)
Amortization of interest rate contracts	2,508						2,252	256
Conversion of redeemable partnership units	0			(50,885)				50,885
Equity, value at Dec. 31, 2014	7,902,936	$ 1,531	$ 200,000	6,270,257	(762,464)	(2,722)	(9,304)	2,205,638
Equity, shares at Dec. 31, 2014		153,114,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of operating partnership units to Common Stock, shares		424,000
Conversion of operating partnership units to Common Stock, value	0	$ 5		14,338				(14,343)
Allocated net income for the year	794,791				583,106			211,685
Dividends/distributions declared	(671,041)				(601,594)			(69,447)
Shares issued pursuant to stock purchase plan, shares		6,000
Shares issued pursuant to stock purchase plan, value	780			780
Net activity from stock option and incentive plan, shares		36,000
Net activity from stock option and incentive plan, value	40,265			5,814				34,451
Acquisition of redeemable noncontrolling interest in property partnership	(1,586)			(1,586)				1,053
Sale of an interest in property partnerships	0			(1,053)
Proceeds from Noncontrolling Interests	2,705							2,705
Distributions to noncontrolling interests in property partnerships	(170,049)							(170,049)
Dissolution of a property partnership	(4,082)							(4,082)
Effective portion of interest rate contracts	(10,302)						(7,061)	(3,241)
Amortization of interest rate contracts	2,510						2,251	259
Conversion of redeemable partnership units	0			17,137				(17,137)
Equity, value at Dec. 31, 2015	$ 7,886,927	$ 1,536	200,000	6,305,687	(780,952)	(2,722)	(14,114)	2,177,492
Equity, shares at Dec. 31, 2015	153,579,966	153,580,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of operating partnership units to Common Stock, shares		191,000
Conversion of operating partnership units to Common Stock, value	$ 0	$ 2		6,459				(6,461)
Allocated net income for the year	569,977				512,785			57,192
Dividends/distributions declared	(474,614)				(425,527)			(49,087)
Shares issued pursuant to stock purchase plan, shares		6,000
Shares issued pursuant to stock purchase plan, value	730			730
Net activity from stock option and incentive plan, shares		13,000
Net activity from stock option and incentive plan, value	31,910			3,979				27,931
Sale of an interest in property partnerships	0			1,195				(1,195)
Proceeds from Noncontrolling Interests	11,951							11,951
Distributions to noncontrolling interests in property partnerships	(51,564)							(51,564)
Effective portion of interest rate contracts	(47,144)						(41,502)	(5,642)
Amortization of interest rate contracts	3,751						3,365	386
Conversion of redeemable partnership units	0			15,374				(15,374)
Equity, value at Dec. 31, 2016	$ 7,931,924	$ 1,538	$ 200,000	$ 6,333,424	$ (693,694)	$ (2,722)	$ (52,251)	$ 2,145,629
Equity, shares at Dec. 31, 2016	153,790,175	153,790,000