CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Revenues:
Product	$ 243,722	$ 239,403	$ 689,125	$ 664,918
Service	136,683	115,812	384,561	351,643
Total revenues	380,405	355,215	1,073,686	1,016,561
Cost of revenues:
Product	139,683	145,976	392,311	402,214
Service	87,600	71,233	237,880	210,107
Total cost of revenues	227,283	217,209	630,191	612,321
Gross Profit	153,122	138,006	443,495	404,240
Operating expenses:
Selling, general, and administrative	75,953	73,922	236,767	227,583
Research and development	10,415	9,196	29,579	26,867
Restructuring expenses	(386)	1,164	(570)	1,522
Total operating expenses	85,982	84,282	265,776	255,972
Income (loss) from operations	67,140	53,724	177,719	148,268
Non-operating expenses, net:
Interest expense	4,207	3,005	10,586	9,083
Interest income and miscellaneous expense	(338)	(373)	(629)	(948)
Total non-operating expenses, net	3,869	2,632	9,957	8,135
Income (loss) before income tax expense (benefit)	63,271	51,092	167,762	140,133
Income tax expense (benefit)	15,174	17,443	49,166	48,189
Net (loss) income	$ 48,097	$ 33,649	$ 118,596	$ 91,944
Net income (loss) per common share
Basic	$ 0.82	$ 0.58	$ 2.04	$ 1.57
Diluted	$ 0.82	$ 0.58	$ 2.02	$ 1.55
Cash dividends declared per common share outstanding	$ 0.19	$ 0.17	$ 0.55	$ 0.49