STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Dec. 31, 2012

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						Nine Months Ended
	December 31,						December 31,
(in thousands)	2012			2011			2012			2011
Cost of revenues	$	507		$	559		$	1,629		$	1,664
Research, development and engineering	1,336			953			3,715			2,928
Selling, general and administrative	2,848			3,067			8,829			8,675
Stock-based compensation included in operating expenses	4,184			4,020			12,544			11,603
Total stock-based compensation	4,691			4,579			14,173			13,267
Income tax benefit	(1,342		)	(1,448		)	(4,256		)	(4,172		)
Total stock-based compensation, net of tax	$	3,349		$	3,131		$	9,917		$	9,095

Summary of Stock Option Activity [Table Text Block]

The following is a summary of the Company’s stock option activity during the nine months ended December 31, 2012:

	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, 2012	3,304		$	26.47
Options granted	428		$	33.23
Options exercised	(444	)	$	23.89
Options forfeited or expired	(143	)	$	34.81
Outstanding at December 31, 2012	3,145		$	27.38	3.6	$	27,472
Vested and expected to vest at December 31, 2012	3,107		$	27.30	3.6	$	27,372
Exercisable at December 31, 2012	2,294		$	24.98	2.7	$	25,355

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 nine months ended December 31, 2012:

	Number of Shares		Weighted Average Grant Date Fair Value
	(in thousands)
Non-vested at March 31, 2012	815		$	33.37
Restricted stock granted	576		$	32.13
Restricted stock vested	(242	)	$	31.21
Restricted stock forfeited	(77	)	$	32.18
Non-vested at December 31, 2012	1,072		$	33.28

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						Nine Months Ended
	December 31,						December 31,
Employee Stock Options	2012			2011			2012			2011
Expected volatility	41.2		%	48.1		%	41.8		%	45.6		%
Risk-free interest rate	0.6		%	0.6		%	0.6		%	1.1		%
Expected dividends	1.2		%	0.6		%	1.2		%	0.6		%
Expected life (in years)	4.3			4.0			4.3			4.0
Weighted-average grant date fair value	$	10.10		$	11.86		$	10.31		$	12.08
ESPP
Expected volatility							38.4		%	38.7		%
Risk-free interest rate							0.1		%	0.1		%
Expected dividends							1.1		%	0.6		%
Expected life (in years)							0.5			0.5
Weighted-average grant date fair value							$	8.95		$	8.00