Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2016

Stock-Based Compensation [Abstract]

Schedule Of Assumptions Used To Estimate Fair Value Of Stock Options

	For the three months ended
	March 31,
	2016	2015
Risk free interest rate	1.33% - 1.43%	1.31% - 1.45%
Dividend yield	0.0%	0.0%
Expected volatility	20.0%	20.0%
Expected lives	4.7 years	4.6 years

Company's Activities With Respect To Its Stock Options

				Weighted-
		Weighted-		Average
		Average		Remaining
	Number	Exercise Price		Contractual	Aggregate
	of Shares	Per Share		Life (in years)	Intrinsic Value
Outstanding at December 31, 2015	3,794	$	84.66
Granted	1,337	$	96.58
Exercised	(203)	$	33.44
Canceled	(35)	$	105.54
Outstanding at March 31, 2016	4,893	$	89.89	5.1	$	75,392
Exercisable at March 31, 2016	2,015	$	72.53	3.7	$	61,924
Unvested at March 31, 2016	2,878	$	102.06	6.1	$	13,468

Company's Restricted Stock Unit Activity

		Weighted-
		Average
		Grant Date
	Number of	Fair Value per
	Units	Share
	(in thousands)
Outstanding at December 31, 2015	277	$	97.14
Granted	131	$	96.58
Vested	(107)	$	83.84
Forfeited/canceled	(4)	$	104.43
Outstanding at March 31, 2016	297	$	101.59