Consolidated Statement of Shareholders' Equity - 3 months ended Apr. 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	24,461			24,461
Exercise of common stock options (in shares)		25,000
Exercise of common stock options	460	$ 0	460	0
Stock-based compensation (in shares)		506,000
Stock-based compensation	3,704	$ 5	3,699	0
Repurchases of common stock (in shares)		(2,424,000)
Repurchases of common stock	$ (54,794)	$ (24)	(4,159)	(50,611)
Balance (in shares) at Apr. 01, 2017	41,676,000	41,676,000
Balance at Apr. 01, 2017	$ 134,151	$ 417	$ 0	$ 133,734