Income Taxes - A Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
A reconciliation of the beginning and ending amount of unrecognized tax benefits
Balance at the beginning of the year	$ 1,029	$ 937	$ 861
Additions based upon tax positions related to the current year	73	75	73
Additions based upon tax positions related to the prior year	3	17
Reductions based upon tax positions related to the prior year			3
Balance at the end of the year	$ 1,105	$ 1,029	$ 937