Equity Repurchases of Common Stock (Details) - USD ($) shares in Thousands, $ in Thousands				3 Months Ended	6 Months Ended
	Jul. 17, 2015	Jul. 08, 2015	Feb. 19, 2014	Jun. 28, 2015	Jun. 28, 2015	Jun. 29, 2014	Jun. 03, 2015	Jun. 01, 2015	Aug. 31, 2014	Jan. 31, 2014
$1.4 Billion Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount								$ 1,400,000
Tender Offer and Purchase Agreement [Domain]
Stock Repurchase Program, Authorized Amount							$ 850,000
Tender Offer [Member]
Stock Repurchase Program, Authorized Amount							639,000
Stock Repurchase Program, Cost Incurred				$ 1,489
Tender Offer [Member] | Subsequent Event [Member]
Treasury Stock, Shares, Acquired		55,808
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions		$ 639,000
Purchase agreement [Member]
Stock Repurchase Program, Authorized Amount							$ 211,000
Purchase agreement [Member] | Subsequent Event [Member]
Treasury Stock, Shares, Acquired	18,416
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions	$ 210,867
$100 Million Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount									$ 100,000
Stock Repurchase Program, Cost Incurred					$ 86
Treasury Stock, Shares, Acquired					5,655
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions					$ 61,631
$275 Million Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount										$ 275,000
Stock Repurchase Program, Cost Incurred						$ 2,275
Treasury Stock, Shares, Acquired			29,730
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions			$ 275,000