Investments and Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 28, 2013	Mar. 30, 2013
Amortized cost of available-for-sale investments in debt securities with contractual maturities
Cost of investments in debt securities due in less than one year	$ 126,849	$ 104,316
Cost of investments in debt securities due after ten years	2,150	2,150
Total cost of investments in debt securities	128,999	106,466
Estimated fair value of investments in debt securities due in less than one year	126,853	104,315
Estimated fair value of investments in debt securities due after ten years	2,150	2,150
Estimated fair value	$ 129,003	$ 106,465