Balance Sheet Detail (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Apr. 01, 2012
Inventories, net
Raw materials	$ 7,041	$ 6,457
Work-in-process	31,185	38,843
Finished goods	23,257	26,480
Total inventories, net	61,483	71,780
Property, pant and equipment, net
Property, plant and equipment, gross	354,765	346,417
Less: accumulated depreciation	(278,624)	(276,433)
Total property, plant and equipment, net	76,141	69,984
Other accrued liabilities
Contingent consideration, Current	4,500	0
Other Accrued Liabilities, Current	15,534	13,443
Total other accrued liabilities	20,034	13,443
Other long-term obligations
Deferred compensation related liabillities	17,651	14,869
Contingent consideration, non-current	1,500	0
Other	976	1,625
Total other long-term liabilities	20,127	16,494
Land [Member]
Property, pant and equipment, net
Property, plant and equipment, gross	11,882	11,665
Machinery and Equipment [Member]
Property, pant and equipment, net
Property, plant and equipment, gross	295,269	290,028
Building and Leasehold Improvements [Member]
Property, pant and equipment, net
Property, plant and equipment, gross	$ 47,614	$ 44,724