Schedule of Fixed Income Securities in Unrealized Loss Positions (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2013
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	$ 510,044
Unrealized Losses Less Than 12 Months - Unrealized	(2,102)
Unrealized Losses 12 Months or Greater - Fair Value	7,270
Unrealized Losses 12 Months or Greater - Unrealized	(181)
Total - Fair Value	517,314
Total - Unrealized	(2,283)
Municipal Notes And Bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	38,907
Unrealized Losses Less Than 12 Months - Unrealized	(141)
Total - Fair Value	38,907
Total - Unrealized	(141)
US Treasury and Agencies
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	58,400
Unrealized Losses Less Than 12 Months - Unrealized	(116)
Total - Fair Value	58,400
Total - Unrealized	(116)
Government-Sponsored Enterprises
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	14,988
Unrealized Losses Less Than 12 Months - Unrealized	(40)
Total - Fair Value	14,988
Total - Unrealized	(40)
Foreign Government Bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	8,162
Unrealized Losses Less Than 12 Months - Unrealized	(8)
Total - Fair Value	8,162
Total - Unrealized	(8)
Corporate Notes And Bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	302,417
Unrealized Losses Less Than 12 Months - Unrealized	(977)
Unrealized Losses 12 Months or Greater - Fair Value	715
Unrealized Losses 12 Months or Greater - Unrealized	(20)
Total - Fair Value	303,132
Total - Unrealized	(997)
Mortgage Backed Securities - Residential
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	25,013
Unrealized Losses Less Than 12 Months - Unrealized	(322)
Total - Fair Value	25,013
Total - Unrealized	(322)
Mortgage Backed Securities - Commercial
Schedule of Available-for-sale Securities [Line Items]
Unrealized Losses Less Than 12 Months - Fair Value	62,157
Unrealized Losses Less Than 12 Months - Unrealized	(498)
Unrealized Losses 12 Months or Greater - Fair Value	6,555
Unrealized Losses 12 Months or Greater - Unrealized	(161)
Total - Fair Value	68,712
Total - Unrealized	$ (659)