Income Taxes (Significant Components Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Mar. 26, 2011
Deferred tax assets:
Inventory valuation	$ 3,240	$ 4,494
Accrued expenses and allowances	3,656	3,017
Net operating loss carryforwards	105,220	131,331
Research and development tax credit carryforwards	36,032	37,464
State tax credit carryforwards	244	250
Capitalized research and development	9,779	14,773
Depreciation and Amortization		159
Other	18,747	14,807
Total deferred tax assets	176,918	206,295
Valuation allowance for deferred tax assets	(29,075)	(68,380)
Net deferred tax assets	147,843	137,915
Deferred tax liabilities:
Depreciation and amortization	287
Acquisition intangibles	5,348	5,861
Total deferred tax liabilities	5,635	5,861
Total net deferred tax assets	$ 142,208	$ 132,054