Share-based Compensation, Options (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 27, 2017	Jun. 28, 2016
Aggregate Intrinsic Value
Proceeds from exercise of stock options	$ 1,291	$ 1,866
Stock Options
Shares
Outstanding at the beginning of the period (in shares)	118,073
Cancelled/Expired (in shares)	(2,650)
Exercised (in shares)	(92,857)
Outstanding at the end of the period (in shares)	22,566
Exercisable at the end of period (in shares)	22,566
Stock options vested (in shares)	0	0
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 13.57
Cancelled/Expired (in dollars per share)	15.73
Exercised (in dollars per share)	13.91
Outstanding at the end of the period (in dollars per share)	11.91
Exercisable at the end of the period (in dollars per share)	$ 11.91
Weighted-Average Remaining Contractual Term
Outstanding at the end of the period	3 months 18 days
Exercisable at the end of the period	3 months 18 days
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)	$ 882
Exercisable at the end of the period (in dollars)	882
Intrinsic value of options exercised (in dollars)	3,100	$ 4,600
Proceeds from exercise of stock options	1,300	1,900
Excess tax benefit recognized within the income tax provision	$ 800
Excess tax benefit recorded in additional paid-in capital		$ 1,300