Net Income per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012
Reconciliation of Net Income per Common Share [Line Items]
Net income	$ 9,926	$ 16,973	$ 33,397	$ 39,390
Basic weighted-average shares outstanding	55,029,000	55,719,000	55,062,000	55,680,000
Options	539,000	1,129,000	613,000	1,099,000
Restricted shares	419,000	546,000	426,000	588,000
Diluted weighted-average shares outstanding	55,987,000	57,394,000	56,101,000	57,367,000
Net income per share – basic	$ 0.18	$ 0.30	$ 0.61	$ 0.71
Net income per share – diluted	$ 0.18	$ 0.30	$ 0.60	$ 0.69
Stock Options [Member]
Reconciliation of Net Income per Common Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,300,000	300,000	1,300,000	300,000