STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Mar. 31, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation Expense Included in Statements of Operations

The following table summarizes the amount of stock-based compensation expense included in the consolidated statements of operations for the periods presented:

	Fiscal Year Ended March 31,
(in thousands)	2014			2013			2012
Cost of revenues	$	2,554		$	2,020		$	2,212
Research, development and engineering	6,404			4,842			3,917
Selling, general and administrative	14,222			11,488			11,352
Stock-based compensation expense included in operating expenses	20,626			16,330			15,269
Total stock-based compensation	23,180			18,350			17,481
Income tax benefit	(6,790		)	(5,479		)	(5,463		)
Total stock-based compensation expense, net of tax	$	16,390		$	12,871		$	12,018

Summary of Stock Option Activity

The following is a summary of the Company’s stock option activity during fiscal year 2014:

	Options Outstanding
	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Aggregate Intrinsic Value
	(in thousands)				(in years)	(in thousands)
Outstanding at March 31, 2013	2,415		$	27.96
Options granted	297		$	44.75
Options exercised	(765	)	$	24.39
Options forfeited or expired	(13	)	$	33.30
Outstanding at March 31, 2014	1,934		$	31.91	4.0	$	22,190
Vested and expected to vest at March 31, 2014	1,900		$	31.75	3.9	$	22,075
Exercisable at March 31, 2014	1,377		$	28.83	3.3	$	19,675

Summary of Restricted Stock Activity

The following is a summary of the Company’s restricted stock activity during fiscal year 2014:

	Number of Shares		Weighted Average Grant Date Fair Value
	(in thousands)
Non-vested at March 31, 2013	1,025		$	33.34
Restricted stock granted	582		$	46.02
Restricted stock vested	(385	)	$	33.17
Restricted stock forfeited	(50	)	$	37.55
Non-vested at March 31, 2014	1,172		$	39.52

Valuation Assumptions

he Company estimates the fair value of stock options and ESPP shares using a Black-Scholes option valuation model.  At the date of grant, the Company estimated the fair value of each stock option grant and purchase right granted under the ESPP using the following weighted average assumptions:

	Employee Stock Options									ESPP
Fiscal Year Ended March 31,	2014			2013			2012			2014			2013			2012
Expected volatility	32.2		%	41.8		%	45.3		%	26.5		%	32.4		%	37.3		%
Risk-free interest rate	0.9		%	0.6		%	1.0		%	0.1		%	0.1		%	0.1		%
Expected dividends	0.9		%	1.2		%	0.6		%	0.9		%	1.0		%	0.6		%
Expected life (in years)	4.2			4.3			4.0			0.5			0.5			0.5
Weighted-average grant date fair value	$	11.15		$	10.31		$	12.06		$	9.62		$	9.00		$	8.69