Equity (Treasury Stock) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Treasury Shares
Number of shares of common stock repurchased (in shares)	296,047	268,798
Total cost of repurchase of treasury shares	$ 16,474	$ 10,929
Open market repurchases
Treasury Shares
Number of shares of common stock repurchased (in shares)	183,300	157,283
Total cost of repurchase of treasury shares	9,820	6,458
2007 Incentive Plan
Treasury Shares
Number of shares of common stock repurchased (in shares)	112,747	111,515
Total cost of repurchase of treasury shares	$ 6,654	$ 4,471