STOCK BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Expense Resulting from Stock Option Awards, Restricted stock units ("RSU") and ESPP

The following table presents the total stock-based compensation expense resulting from stock option awards, restricted stock units (“RSUs”), and the ESPP included in the Condensed Consolidated Statements of Income:

In thousands
	Three Months Ended March 31,
	2016		2015
Cost of revenues – stock option plan	$	15	$	23
Selling, general and administrative – stock option plan		4,752		4,729
Selling, general and administrative – RSUs		559		346
Selling, general and administrative – ESPP		779		389
Total pre-tax expense	$	6,105	$	5,487

Stock Option Activity

Stock option activity for the three months ended March 31, 2016, is summarized as follows:

	Number of Options			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Life		Total Aggregate Intrinsic Value
						(in years)		(in thousands)
Outstanding at beginning of year		5,334,803		$	92.02
Granted		1,008,569			111.29
Exercised		(306,088	)		73.22
Forfeited		(28,412	)		118.19
Canceled or expired		(1,939	)		86.92
Outstanding at March 31, 2016		6,006,933			96.10		5.92	$	185,247
Exercisable at March 31, 2016		3,225,121			80.59		4.93	$	147,947

Intrinsic Value of Options Exercised

The following table sets forth the total intrinsic value of options exercised:

	Three Months Ended March 31,
	2016		2015
Total intrinsic value of options exercised	$	13,229	$	29,525

Assumptions used in Black-Scholes Model

The estimated fair value of stock options at the time of the grant using the Black-Scholes option pricing model was as follows:

	Three Months Ended March 31,
	2016			2015
Stock options granted (shares)		1,008,569			860,534
Weighted average fair value at grant date (per share)	$	20.19		$	22.84
Assumptions:
Expected term (in years)		4.76			4.79
Expected volatility		18.02	%		16.62	%
Expected dividend yield		—	%		—	%
Risk free interest rate		1.26	%		1.48	%

Restricted Stock Units Activity

A summary of the status of our non-vested RSUs and changes during the three months ended March 31, 2016, are as follows:

	Number of Options		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life		Total Aggregate Intrinsic Value
					(in years)		(in thousands)
Non-vested at beginning of year		71,451	$	101.29
Granted		53,267		111.12
Non-vested at March 31, 2016		124,718		105.57		2.34	$	15,738