Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Weighted Average Assumptions Used for Options Granted

The following weighted average assumptions were used for options granted:

	Years ended December 31,
	2015			2014			2013
Expected life (in years)		6.0			6.0			6.4
Expected volatility		28.3	%		30.9	%		32.4	%
Risk-free interest rate		1.7	%		1.8	%		1.4	%
Expected forfeiture rate		1.7	%		3.0	%		3.0	%

Summary of Share-Based Compensation Expense Related to Share-Based Awards

The following table summarizes share-based compensation expense related to share-based awards which is recorded in the statements of comprehensive income:

	Years ended December 31,
	2015			2014			2013
Cost of software services, maintenance and subscriptions	$	3,380		$	2,177		$	1,509
Selling, general and administrative expenses		16,802			12,642			10,144
Total share-based compensation expenses		20,182			14,819			11,653
Tax benefit		(5,986	)		(4,237	)		(3,363	)
Net decrease in net income	$	14,196		$	10,582		$	8,290

Stock Option Activity

Options granted, exercised, forfeited and expired are summarized as follows:

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2012		5,711		$	20.86
Granted		1,453			67.08
Exercised		(1,443	)		12.68
Forfeited		(1	)		68.17
Outstanding at December 31, 2013		5,720			34.66
Granted		675			94.15
Exercised		(855	)		17.17
Forfeited		(3	)		37.44
Outstanding at December 31, 2014		5,537			44.61
Granted		747			145.71
Exercised		(1,118	)		20.71
Forfeited		(2	)		19.61
Outstanding at December 31, 2015		5,164			64.43		7	$	568,239
Exercisable at December 31, 2015		1,940			40.69		6	$	259,257

Other information pertaining to option activity was as follows during the twelve months ended December 31:

	2015		2014		2013
Weighted average grant-date fair value of stock options granted	$	45.17	$	31.32	$	23.27
Total intrinsic value of stock options exercised		149,542		69,768		99,393