STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Jun. 30, 2013

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

Stock-Based Compensation Expense Included in Statements of Operations [Table Text Block]

The following table summarizes the amount of stock-based compensation included in the condensed consolidated statements of operations:

	Three Months Ended
	June 30,
(in thousands)	2013			2012
Cost of revenues	$	535		$	596
Research, development and engineering	1,368			1,124
Selling, general and administrative	3,085			2,900
Stock-based compensation included in operating expenses	4,453			4,024
Total stock-based compensation	4,988			4,620
Income tax benefit	(1,437		)	(1,382		)
Total stock-based compensation, net of tax	$	3,551		$	3,238

Summary of Stock Option Activity [Table Text Block]

The following is a summary of the Company’s stock option activity during the three months ended June 30, 2013:

	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	151		$	45.68
Options exercised	(549	)	$	23.97
Options forfeited or expired	(8	)	$	31.63
Outstanding at June 30, 2013	2,009		$	30.36	4.2	$	27,517
Vested and expected to vest at June 30, 2013	1,960		$	30.17	4.2	$	27,178
Exercisable at June 30, 2013	1,298		$	27.09	3.3	$	21,844

Summary of Restricted Stock Activity [Table Text Block]

Restricted stock consists of awards of restricted stock and restricted stock units ("RSUs"). The following is a summary of the Company’s restricted stock activity during the three months ended June 30, 2013:

	Number of Shares		Weighted Average Grant Date Fair Value
	(in thousands)
Non-vested at March 31, 2013	1,025		$	33.34
Restricted stock granted	517		$	46.11
Restricted stock vested	(226	)	$	32.35
Restricted stock forfeited	(11	)	$	36.29
Non-vested at June 30, 2013	1,305		$	38.55

Valuation Assumptions [Table Text Block]

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:

	Three Months Ended
	June 30,
Employee Stock Options	2013			2012
Expected volatility	34.0		%	41.7		%
Risk-free interest rate	0.6		%	0.6		%
Expected dividends	0.9		%	1.3		%
Expected life (in years)	4.2			4.3
Weighted-average grant date fair value	$	11.86		$	10.30