Stockholders' Equity (Narrative) (Details) - USD ($) shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jul. 21, 2015	Oct. 17, 2014	Oct. 21, 2008
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased (in shares)				3,000	6,000
Costs for repurchase of common stock	$ 81,036	$ 44,622
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	300
Shares Repurchased And Retired Related to Net of Issuances Shares, Shares	73	47
Payments Related to Tax Withholding for net share settlement	$ 2,300	$ 1,500
Repurchase plan authorized in Oct 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchased and Retired During Period, Shares		1,300
Costs for repurchase of common stock		$ 43,100
Repurchase plan authorized in Oct 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchased and Retired During Period, Shares	2,700
Costs for repurchase of common stock	$ 84,600
Pending settlement relating to repurchase of common stock	$ 5,800
Repurchase plan authorized in Oct 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased (in shares)			3,000