Commitments and Contingencies Sales Return Liability (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Sales return liability [Roll Forward]
Balance at beginning of year	$ 5,330	$ 4,402
Additions that reduce net sales	12,963	13,066
Deductions from reserves	(13,230)	(12,047)
Acquired sales return reserve	50	0
Balance at end of period	$ 5,113	$ 5,421