Net Income per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Reconciliation of Net Income per Common Share [Line Items]
Net income	$ 20,259	$ 26,209	$ 53,656	$ 65,599
Basic weighted-average shares outstanding	54,854,000	55,444,000	54,992,000	55,601,000
Diluted weighted-average shares outstanding	55,748,000	56,986,000	55,990,000	57,202,000
Net income per share – basic (in USD per share)	$ 0.37	$ 0.47	$ 0.98	$ 1.18
Net income per share – diluted (in USD per share)	$ 0.36	$ 0.46	$ 0.96	$ 1.15
Stock Options [Member]
Reconciliation of Net Income per Common Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	600,000	300,000	1,300,000	300,000
Stock Options [Member]
Reconciliation of Net Income per Common Share [Line Items]
Effect of dilutive securities	531,000	1,121,000	589,000	1,085,000
Restricted Stock [Member]
Reconciliation of Net Income per Common Share [Line Items]
Effect of dilutive securities	363,000	421,000	409,000	516,000