Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2016	Dec. 29, 2015
Operating Loss Carryforwards [Line Items]
Adjustment to equity from release of tax reserve	$ 2,439
US general business credit carryforwards	21,271	$ 18,915
U.S.
Operating Loss Carryforwards [Line Items]
US general business credit carryforwards	$ 21,300