Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Share-Based Compensation [Abstract]

Schedule Of Selected Financial Impact Of Share-Based Compensation

		For the Years Ended December 31,
		2016			2015			2014
Share-based compensation expense included in cost of revenue	$	2,305		$	2,138		$	1,937
Share-based compensation expense included in operating expenses		17,586			17,746			16,162
Total share-based compensation expense included in consolidated statements of income		19,891			19,884			18,099
Income tax benefit resulting from share-based compensation arrangements		(6,143	)		(6,229	)		(6,107	)
Net impact of share-based compensation on net income	$	13,748		$	13,655		$	11,992

Schedule Of Weighted Averages Of The Assumptions Used In Estimating The Fair Value Of Stock Option Awards

	For the Years Ended December 31,
		2016			2015			2014
Expected stock price volatility		25	%		23	%		28	%
Expected term, in years		5.7			5.6			5.7
Risk-free interest rate		1.2	%		1.5	%		1.5	%
Weighted average fair value of options granted	$	17.87		$	19.72		$	18.07

Schedule Of Stock Option Activity

	Number of Options (000)	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value ($000)
Outstanding as of December 31, 2015	3,384	$	49.76
Granted	745		69.07
Exercised	(838)		37.04
Forfeited	(115)		59.34
Expired	-		-
Outstanding as of December 31, 2016	3,176	$	57.31	5.3	$	190,424
Fully vested as of December 31, 2016	1,510	$	46.92	3.2	$	106,255
Fully vested and expected to vest as of December 31, 2016	3,034	$	56.78	5.2	$	183,550

Schedule Of Restricted Stock Unit Activity

	Number of Units (000)	Weighted Average Grant-Date Fair Value
Nonvested as of December 31, 2015	498	$	58.94
Granted	173		69.14
Vested	(170)		52.60
Forfeited	(33)		60.46
Nonvested as of December 31, 2016	468	$	64.88
Expected to vest as of December 31, 2016	418	$	64.44