Fair Value of Financial Instruments (Details 2) (Assets and liabilities measured at fair value on recurring basis, USD $)	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011
Fair value assets reconciliation of changes
Balance at the beginning of the period		$ 48,668,000
Settlements		(33,368,000)
Unrealized gains		179,000
Net recognized gains (losses)		2,021,000
Balance at the end of the period		17,500,000
Auction rate securities
Fair value assets reconciliation of changes
Balance at the beginning of the period	17,500,000	45,575,000
Settlements	(500,000)	(31,142,000)
Unrealized gains	477,000	179,000
Net recognized gains (losses)		2,888,000
Balance at the end of the period	17,477,000	17,500,000
Auction-rate securities purchased through UBS AG, par value		23,500,000
Put Option
Fair value assets reconciliation of changes
Balance at the beginning of the period		3,093,000
Settlements		(2,226,000)
Net recognized gains (losses)		$ (867,000)