Commitments and Contingencies Sales Return Liability (Details) - USD ($) $ in Thousands	6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016
Sales return liability [Roll Forward]
Balance at beginning of year	$ 15,222	$ 20,562
Additions that reduce net sales	32,434	35,419
Deductions from reserves	(35,054)	(40,226)
Balance at end of period	$ 12,602	$ 15,755