Schedule of Cash, Cash Equivalents, Short-Term Investments and Restricted Cash and Investments Unrealized Loss Positions (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2015
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	$ 1,015,683
Unrealized Losses Less Than 12 Months - Gross Unrealized Loss	(1,623)
Unrealized Losses 12 Months or Greater - Fair Value	27,675
Unrealized Losses 12 Months or Greater - Gross Unrealized Loss	(389)
Total - Fair Value	1,043,358
Total - Gross Unrealized Loss	(2,012)
Municipal Notes And Bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	75,497
Unrealized Losses Less Than 12 Months - Gross Unrealized Loss	(51)
Total - Fair Value	75,497
Total - Gross Unrealized Loss	(51)
Corporate Notes And Bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	553,071
Unrealized Losses Less Than 12 Months - Gross Unrealized Loss	(963)
Unrealized Losses 12 Months or Greater - Fair Value	2,709
Unrealized Losses 12 Months or Greater - Gross Unrealized Loss	(10)
Total - Fair Value	555,780
Total - Gross Unrealized Loss	(973)
US Treasury and Agencies
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	189,671
Unrealized Losses Less Than 12 Months - Gross Unrealized Loss	(42)
Total - Fair Value	189,671
Total - Gross Unrealized Loss	(42)
Government-Sponsored Enterprises
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	50,215
Unrealized Losses Less Than 12 Months - Gross Unrealized Loss	(38)
Total - Fair Value	50,215
Total - Gross Unrealized Loss	(38)
Foreign Government Bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	29,721
Unrealized Losses Less Than 12 Months - Gross Unrealized Loss	(39)
Total - Fair Value	29,721
Total - Gross Unrealized Loss	(39)
Mortgage Backed Securities - Residential
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	13,130
Unrealized Losses Less Than 12 Months - Gross Unrealized Loss	(52)
Unrealized Losses 12 Months or Greater - Fair Value	2,347
Unrealized Losses 12 Months or Greater - Gross Unrealized Loss	(92)
Total - Fair Value	15,477
Total - Gross Unrealized Loss	(144)
Mortgage Backed Securities - Commercial
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	100,667
Unrealized Losses Less Than 12 Months - Gross Unrealized Loss	(433)
Unrealized Losses 12 Months or Greater - Fair Value	22,619
Unrealized Losses 12 Months or Greater - Gross Unrealized Loss	(287)
Total - Fair Value	123,286
Total - Gross Unrealized Loss	$ (720)