Summary of Securities (Detail) (USD $) In Millions, unless otherwise specified	Sep. 29, 2013	Dec. 30, 2012
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Market Value	$ 2.5
Short-term Investments
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Amortized Cost	0.2	0.1
Gross Unrealized Losses
Market Value	0.2	0.1
Short-term Investments | U.S. Treasury securities and obligations of U.S. government agencies
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Amortized Cost	0.1	0.1
Gross Unrealized Losses
Market Value	0.1	0.1
Short-term Investments | Corporate Debt Securities
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Amortized Cost	0.1
Gross Unrealized Losses
Market Value	0.1
Long-Term Investments
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Amortized Cost	2.1	2.3
Gross Unrealized Gains	0.2	0.3
Gross Unrealized Losses
Market Value	2.3	2.6
Long-Term Investments | U.S. Treasury securities and obligations of U.S. government agencies
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Amortized Cost	2.0	2.1
Gross Unrealized Gains	0.2	0.3
Gross Unrealized Losses
Market Value	2.2	2.4
Long-Term Investments | Corporate Debt Securities
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Amortized Cost	0.1	0.2
Gross Unrealized Losses
Market Value	0.1	0.2
Long-Term Investments | Auction Rate Securities
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Gross Unrealized Losses