Investment Securities - Schedule of Unrealized Losses by Investment Category (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Apr. 01, 2012
Schedule of Available-for-sale Securities [Line Items]
Fair value of less than 12 months	$ 38,753	$ 158,210
Unrealized losses of less than 12 months	(75)	(315)
Fair value of 12 months or greater		139
Unrealized losses of 12 months or greater		(4)
Fair value, Total	38,753	158,349
Unrealized losses, Total	(75)	(319)
U.S. government and agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of less than 12 months	4,502	76,239
Unrealized losses of less than 12 months	(1)	(78)
Fair value of 12 months or greater
Unrealized losses of 12 months or greater
Fair value, Total	4,502	76,239
Unrealized losses, Total	(1)	(78)
Corporate debt obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of less than 12 months	24,203	66,997
Unrealized losses of less than 12 months	(30)	(166)
Fair value of 12 months or greater
Unrealized losses of 12 months or greater
Fair value, Total	24,203	66,997
Unrealized losses, Total	(30)	(166)
Asset and mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of less than 12 months	10,048	12,996
Unrealized losses of less than 12 months	(44)	(69)
Fair value of 12 months or greater		139
Unrealized losses of 12 months or greater		(4)
Fair value, Total	10,048	13,135
Unrealized losses, Total	(44)	(73)
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of less than 12 months		1,978
Unrealized losses of less than 12 months		(2)
Fair value of 12 months or greater
Unrealized losses of 12 months or greater
Fair value, Total		1,978
Unrealized losses, Total		$ (2)