Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Sep. 27, 2014	Oct. 03, 2015	Sep. 27, 2014
Income Taxes
Income tax expense	$ 467	$ 3,501	$ 2,112	$ 10,908
Effective income tax rate (as a percent)	4.50%	38.40%	8.10%	28.00%
Gross unrecognized tax benefits	$ 3,700		$ 3,700
Amount of estimated decrease in unrecognized tax benefits	$ 900		$ 900