Net Income per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Apr. 02, 2011
Net Income per Common Share [Abstract]
Net income	$ 22,417	$ 16,583
Reconciliation of weighted-average shares outstanding:
Basic weighted-average shares outstanding (in shares)	55,640,000	54,726,000
Effect of dilutive securities:
Options (in shares)	1,156,000	714,000
Restricted shares (in shares)	644,000	537,000
Diluted weighted-average shares outstanding (in shares)	57,440,000	55,977,000
Net income per share - basic (in dollars per share)	$ 0.40	$ 0.30
Net income per share - diluted (in dollars per share)	$ 0.39	$ 0.30
Potentially Dilutive Stock Options [Member]
Stock options excluded from diluted net income (loss) per share calculation [Abstract]
Potentially dilutive stock options excluded from EPS calculation (in shares)	200,000	2,400,000