Consolidated Statement of Shareholders' Equity - 6 months ended Jul. 01, 2017 - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]
Balance (in shares) at Dec. 31, 2016	43,569,000	43,569,000
Balance at Dec. 31, 2016	$ 160,320	$ 436	$ 0	$ 159,884
Net income	23,683			23,683
Exercise of common stock options (in shares)		180,000
Exercise of common stock options	2,654	$ 2	2,652	0
Stock-based compensation (in shares)		581,000
Stock-based compensation	7,876	$ 6	7,870	0
Repurchases of common stock (in shares)		(3,264,000)
Repurchases of common stock	$ (80,094)	$ (33)	(10,522)	(69,539)
Balance (in shares) at Jul. 01, 2017	41,066,000	41,066,000
Balance at Jul. 01, 2017	$ 114,439	$ 411	$ 0	$ 114,028