Segment Information (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2011	Oct. 01, 2010	Sep. 30, 2011	Oct. 01, 2010	Apr. 01, 2011
Revenues
Product revenues	$ 146,611	$ 127,586	$ 269,157	$ 252,588
Service revenues	76,413	70,303	148,968	137,305
Total revenues	223,024	197,889	418,125	389,893
Operating profits (losses)
Segment operating profit before corporate and amortization of acquired intangible assets	9,723	18,167	15,796	30,116
Amortization of acquired intangible assets	(4,767)	(5,094)	(9,539)	(9,704)
Segment operating profit	4,956	13,073	6,257	20,456
Segment assets
Segment assets	1,525,567		1,525,567		1,405,748
Government Systems [Member]
Revenues
Product revenues	86,621	86,530	161,220	168,362
Service revenues	16,789	8,407	28,359	15,420
Total revenues	103,410	94,937	189,579	183,782
Operating profits (losses)
Amortization of acquired intangible assets	(645)	(823)	(1,296)	(1,092)
Segment operating profit	14,333	12,808	21,713	14,466
Segment assets
Segment assets	231,920		231,920		228,194
Commercial Networks [Member]
Revenues
Product revenues	59,063	39,431	106,359	82,049
Service revenues	5,136	4,881	9,909	7,882
Total revenues	64,199	44,312	116,268	89,931
Operating profits (losses)
Amortization of acquired intangible assets	(884)	(1,033)	(1,767)	(2,136)
Segment operating profit	(2,871)	(2,347)	(6,111)	(3,517)
Segment assets
Segment assets	152,389		152,389		133,158
Satellite Services [Member]
Revenues
Product revenues	927	1,625	1,578	2,177
Service revenues	54,488	57,015	110,700	114,003
Total revenues	55,415	58,640	112,278	116,180
Operating profits (losses)
Amortization of acquired intangible assets	(3,238)	(3,238)	(6,476)	(6,476)
Segment operating profit	(1,739)	7,706	194	19,167
Segment assets
Segment assets	91,858		91,858		93,857
Unallocated Amount to Segment [Member]
Operating profits (losses)
Segment operating profit	0	0	0	44
Segment assets
Segment assets	1,049,400		1,049,400		950,539
Operating Segments [Member]
Segment assets
Segment assets	476,167		476,167		455,209
Intersegment Elimination [Member]
Revenues
Total revenues	0	0	0	0
Operating profits (losses)
Segment operating profit	$ 0	$ 0	$ 0	$ 0