Effects of Foreign Currency Forward Contracts in Cash Flow Hedging Relationships (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 28, 2012	Sep. 30, 2011	Sep. 28, 2012	Sep. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ (454)	$ (77)	$ (586)	$ 83
Amount of Gain or (Loss) Recognized in Accumulated OCI on Derivatives (Effective Portion)	(243)	(670)	(520)	(638)
Derivatives in Cash Flow Hedging Relationships [Member] | Foreign currency forward contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Accumulated OCI on Derivatives (Effective Portion)	(243)	(670)	(520)	(638)
Derivatives in Cash Flow Hedging Relationships [Member] | Foreign currency forward contracts [Member] | Cost of product revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ (454)	$ (77)	$ (586)	$ 83