Net Income per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Net Income per Common Share [Abstract]
Net income	$ 25,603	$ 25,745	$ 49,286	$ 40,130
Basic weighted-average shares outstanding	40,755,000	45,621,000	41,740,000	46,705,000
Dilutive effect of stock-based awards	760,000	729,000	819,000	708,000
Diluted weighted-average shares outstanding	41,515,000	46,350,000	42,559,000	47,413,000
Net income per share – basic (in USD per share)	$ 0.63	$ 0.56	$ 1.18	$ 0.86
Net income per share – diluted (in USD per share)	$ 0.62	$ 0.56	$ 1.16	$ 0.85