Legal Proceedings - Additional Information (Detail) (USD $)			6 Months Ended
Sep. 29, 2012	Mar. 31, 2012	Sep. 29, 2012 All Ring Patent Infringement Prosecution
Gain Contingencies
Letters of credit, amount			$ 19,500,000
Restricted cash, collateral	22,269,000	22,269,000	22,269,000
Patent infringement, damage awarded by court			24,000,000
Patent infringement, interest rate on award			5.00%
Cash bond posted amount			$ 24,000,000

- Definition

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations.

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