Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Share-Based Compensation [Abstract]

Schedule Of Selected Financial Impact Of Share-Based Compensation

		For the Years Ended December 31,
		2015			2014			2013
Share-based compensation expense included in cost of revenue	$	2,138		$	1,937		$	1,841
Share-based compensation expense included in operating expenses		17,746			16,162			14,733
Total share-based compensation expense included in consolidated statements of income		19,884			18,099			16,574
Income tax benefit resulting from share-based compensation arrangements		(6,229	)		(6,107	)		(5,584	)
Net impact of share-based compensation on net income	$	13,655		$	11,992		$	10,990

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

	For the Years Ended December 31,
		2015			2014			2013
Expected stock price volatility		23	%		28	%		32	%
Expected term, in years		5.6			5.7			4.9
Risk-free interest rate		1.5	%		1.5	%		1.0	%
Weighted average fair value of options granted	$	19.72		$	18.07		$	13.59

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, 2014	3,560	$	40.08
Granted	611		78.08
Exercised	(675)		23.65
Forfeited	(112)		53.64
Expired	-
Outstanding as of December 31, 2015	3,384	$	49.76	4.8	$	81,936
Fully vested as of December 31, 2015	1,748	$	39.67	3.0	$	58,132
Fully vested and expected to vest as of December 31, 2015	3,276	$	49.41	4.7	$	80,453

Schedule Of Restricted Stock Unit Activity

	Number of Units (000)	Weighted Average Grant-Date Fair Value
Nonvested as of December 31, 2014	578	$	47.98
Granted	153		78.46
Vested	(196)		43.14
Forfeited	(37)		56.01
Nonvested as of December 31, 2015	498	$	58.94
Expected to vest as of December 31, 2015	456	$	58.52