Cash, Cash Equivalents and Investments (Details 4) (USD $) In Thousands, unless otherwise specified	Apr. 01, 2012
Short-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	$ 97,882
Short-term investments [Member] | Australia [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,399
Short-term investments [Member] | Austria [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	817
Short-term investments [Member] | Canada [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	4,395
Short-term investments [Member] | France [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,072
Short-term investments [Member] | Germany [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	13,317
Short-term investments [Member] | Great Britain [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	20,241
Short-term investments [Member] | Japan [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,697
Short-term investments [Member] | Netherlands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	18,125
Short-term investments [Member] | Supranational [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,009
Short-term investments [Member] | Sweden [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	6,714
Short-term investments [Member] | Switzerland [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,679
Short-term investments [Member] | Norway [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,369
Short-term investments [Member] | Cayman Islands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,076
Short-term investments [Member] | Jersey [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,341
Short-term investments [Member] | United States [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	15,631
Long-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	76,244
Long-term investments [Member] | Austria [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	4,798
Long-term investments [Member] | Belgium [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,824
Long-term investments [Member] | Canada [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,398
Long-term investments [Member] | France [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,112
Long-term investments [Member] | Germany [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	24,522
Long-term investments [Member] | Great Britain [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	10,615
Long-term investments [Member] | Japan [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,891
Long-term investments [Member] | Netherlands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	5,079
Long-term investments [Member] | Sweden [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,101
Long-term investments [Member] | Denmark [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,550
Long-term investments [Member] | Finland [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,911
Long-term investments [Member] | Jersey [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,766
Long-term investments [Member] | Hong Kong [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,749
Long-term investments [Member] | United States [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	10,928
Corporate bonds [Member] | Short-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	58,050
Corporate bonds [Member] | Short-term investments [Member] | Australia [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,399
Corporate bonds [Member] | Short-term investments [Member] | Canada [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,993
Corporate bonds [Member] | Short-term investments [Member] | France [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,072
Corporate bonds [Member] | Short-term investments [Member] | Germany [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	9,125
Corporate bonds [Member] | Short-term investments [Member] | Great Britain [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	11,408
Corporate bonds [Member] | Short-term investments [Member] | Japan [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,697
Corporate bonds [Member] | Short-term investments [Member] | Netherlands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	4,266
Corporate bonds [Member] | Short-term investments [Member] | Sweden [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,038
Corporate bonds [Member] | Short-term investments [Member] | Switzerland [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,679
Corporate bonds [Member] | Short-term investments [Member] | Cayman Islands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,076
Corporate bonds [Member] | Short-term investments [Member] | Jersey [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,341
Corporate bonds [Member] | Short-term investments [Member] | United States [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	13,956
Corporate bonds [Member] | Long-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	43,240
Corporate bonds [Member] | Long-term investments [Member] | Belgium [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,824
Corporate bonds [Member] | Long-term investments [Member] | Canada [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,119
Corporate bonds [Member] | Long-term investments [Member] | France [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,112
Corporate bonds [Member] | Long-term investments [Member] | Germany [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	6,784
Corporate bonds [Member] | Long-term investments [Member] | Great Britain [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	10,615
Corporate bonds [Member] | Long-term investments [Member] | Japan [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,891
Corporate bonds [Member] | Long-term investments [Member] | Netherlands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	5,079
Corporate bonds [Member] | Long-term investments [Member] | Denmark [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,810
Corporate bonds [Member] | Long-term investments [Member] | Jersey [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,766
Corporate bonds [Member] | Long-term investments [Member] | Hong Kong [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,749
Corporate bonds [Member] | Long-term investments [Member] | United States [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	8,491
Agency bonds [Member] | Short-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	27,299
Agency bonds [Member] | Short-term investments [Member] | Austria [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	817
Agency bonds [Member] | Short-term investments [Member] | Canada [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,402
Agency bonds [Member] | Short-term investments [Member] | Germany [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,015
Agency bonds [Member] | Short-term investments [Member] | Great Britain [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	5,613
Agency bonds [Member] | Short-term investments [Member] | Netherlands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	8,092
Agency bonds [Member] | Short-term investments [Member] | Supranational [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,009
Agency bonds [Member] | Short-term investments [Member] | Sweden [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	3,676
Agency bonds [Member] | Short-term investments [Member] | United States [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,675
Agency bonds [Member] | Long-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	12,986
Agency bonds [Member] | Long-term investments [Member] | Austria [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	4,798
Agency bonds [Member] | Long-term investments [Member] | Canada [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,279
Agency bonds [Member] | Long-term investments [Member] | Germany [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,371
Agency bonds [Member] | Long-term investments [Member] | Sweden [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,101
Agency bonds [Member] | Long-term investments [Member] | United States [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,437
Sovereign Bonds [Member] | Short-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	6,223
Sovereign Bonds [Member] | Short-term investments [Member] | Germany [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	2,177
Sovereign Bonds [Member] | Short-term investments [Member] | Netherlands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	4,046
Sovereign Bonds [Member] | Long-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	18,278
Sovereign Bonds [Member] | Long-term investments [Member] | Germany [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	16,367
Sovereign Bonds [Member] | Long-term investments [Member] | Finland [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,911
Covered bonds [Member] | Short-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	4,443
Covered bonds [Member] | Short-term investments [Member] | Great Britain [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,353
Covered bonds [Member] | Short-term investments [Member] | Netherlands [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,721
Covered bonds [Member] | Short-term investments [Member] | Norway [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,369
Covered bonds [Member] | Long-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,740
Covered bonds [Member] | Long-term investments [Member] | Denmark [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,740
Asset-backed securities [Member] | Short-term investments [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	1,867
Asset-backed securities [Member] | Short-term investments [Member] | Great Britain [Member]
Summary of available-for-sale investments held in its international portfolio
Available for sale investments	$ 1,867