Investments and Fair Value Measurements (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 28, 2013	Mar. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	$ 129,003	$ 106,465
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	129,003	106,465
Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	126,853	104,315
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	2,150	2,150
U.S. government/agency securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	88,059	77,987
U.S. government/agency securities [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	88,059	77,987
U.S. government/agency securities [Member] | Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	88,059	77,987
Auction Rate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	2,150	2,150
Auction Rate Securities [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	2,150	2,150
Auction Rate Securities [Member] | Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	2,150	2,150
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	38,794	26,328
Money Market Funds [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	38,794	26,328
Money Market Funds [Member] | Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fair value of financial assets measured at fair value on a recurring basis	$ 38,794	$ 26,328