Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2015	Sep. 30, 2014	Sep. 29, 2015	Sep. 30, 2014
Amounts used for basic and diluted per share calculations
Net Income	$ 32,393	$ 39,214	$ 106,182	$ 130,801
Weighted average number of shares outstanding - basic (in shares)	25,394	26,715	26,011	26,979
Effect of dilutive stock-based employee compensation awards (in shares)	107	98	108	129
Weighted average number of shares outstanding - diluted (in shares)	25,501	26,813	26,119	27,108
Earnings per common share:
Basic (in dollars per share)	$ 1.28	$ 1.47	$ 4.08	$ 4.85
Diluted (in dollars per share)	$ 1.27	$ 1.46	$ 4.07	$ 4.83