Fair Market Value of Investments with Unrealized Losses Not Deemed to be Other-Than Temporarily Impaired (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2013
Schedule of Available-for-sale Securities [Line Items]
Unrealized Loss Position, Less than 12 Months, Fair Value	$ 10,914
Unrealized Loss Position, Less than 12 Months, Gross Unrealized Losses	7
Unrealized Loss Position, Greater than 12 Months, Fair Value
Unrealized Loss Position, Greater than 12 Months, Gross Unrealized Losses
Corporate bonds and medium-term notes
Schedule of Available-for-sale Securities [Line Items]
Unrealized Loss Position, Less than 12 Months, Fair Value	7,802
Unrealized Loss Position, Less than 12 Months, Gross Unrealized Losses	6
Unrealized Loss Position, Greater than 12 Months, Fair Value
Unrealized Loss Position, Greater than 12 Months, Gross Unrealized Losses
Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Unrealized Loss Position, Less than 12 Months, Fair Value	3,112
Unrealized Loss Position, Less than 12 Months, Gross Unrealized Losses	1
Unrealized Loss Position, Greater than 12 Months, Fair Value
Unrealized Loss Position, Greater than 12 Months, Gross Unrealized Losses