Segment Information (Details 3) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2011	Oct. 01, 2010	Sep. 30, 2011	Oct. 01, 2010
Revenue information by geographic area
Revenue information by geographic area - United States	$ 175,760	$ 166,935	$ 329,961	$ 328,100
Total revenue information by geographic area	223,024	197,889	418,125	389,893
Europe, Middle East and Africa [Member]
Revenue information by geographic area
Revenue information by geographic area	30,336	21,587	57,240	42,201
Asia, Pacific [Member]
Revenue information by geographic area
Revenue information by geographic area	4,819	6,012	11,997	12,845
North America other than United States [Member]
Revenue information by geographic area
Revenue information by geographic area	5,489	1,777	9,713	3,099
Latin America [Member]
Revenue information by geographic area
Revenue information by geographic area	$ 6,620	$ 1,578	$ 9,214	$ 3,648