Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Stock-based Compensation [Abstract]

Schedule Of Sharebased Compensation Restricted Operating Partnership Units Earned

				Percentage of
		Total Plan		Notional Amount		Grant Date
Plan Year		Notional Amount		Granted		Fair Value(1)		OPP Units Earned
2016		$	40,000,000		86.7%	$	11,800,000	To be determined in 2019
2015			40,000,000		84.5%		9,120,000	To be determined in 2018
2014			50,000,000		58.9%		8,202,000	297,495	(2)
(1)	Such amounts are being amortized into expense over a five-year period from the date of grant, using a graded vesting attribution model. In the years ended December 31, 2016, 2015 and 2014, we recognized $11,055,000, $15,531,000 and $6,185,000, respectively, of compensation expense related to OPPs. As of December 31, 2016, there was $5,752,000 of total unrecognized compensation cost related to the OPPs, which will be recognized over a weighted-average period of 1.7 years.
(2)	99.5% earned on January 10, 2017.

Schedule Of Share Based Compensation Stock Options Activity

					Weighted-
			Weighted-		Average
			Average		Remaining	Aggregate
			Exercise		Contractual	Intrinsic
		Shares	Price		Term	Value
Outstanding at January 1, 2016		2,827,570	$	60.06
Granted		42,466		92.97
Exercised		(125,724)		56.44
Cancelled or expired		(11,768)		100.49
Outstanding at December 31, 2016		2,732,544	$	65.76	3.1	$	120,360,377
Options vested and expected to vest at
	December 31, 2016	2,737,594	$	60.66	4.1	$	118,170,212
Options exercisable at December 31, 2016		2,642,684	$	59.42	2.9	$	119,269,973

Schedule Of Share Based Payment Award Stock Options Valuation Assumptions

	December 31,
	2016	2015	2014
Expected volatility	35.00 %	35.00 %	36.00 %
Expected life	5.0 years	5.0 years	5.0 years
Risk free interest rate	1.76 %	1.56 %	1.81 %
Expected dividend yield	3.20 %	3.30 %	4.10 %

Schedule Of Sharebased Compensation Restricted Stock And Restricted Stock Units Activity

		Weighted-Average
		Grant-Date
Unvested Shares	Shares	Fair Value
Unvested at January 1, 2016	19,592	$	91.09
Granted	9,973		92.97
Vested	(7,472)		85.80
Cancelled or expired	(1,086)		93.87
Unvested at December 31, 2016	21,007		93.72

Schedule Of Sharebased Compensation Restricted Operating Partnership Units Activity

		Weighted-Average
		Grant-Date
Unvested Units	Units	Fair Value
Unvested at January 1, 2016	639,017	$	80.46
Granted	211,086		87.60
Vested	(289,515)		78.41
Cancelled or expired	(7,554)		92.01
Unvested at December 31, 2016	553,034		87.11