Debt (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	9 Months Ended				1 Months Ended	9 Months Ended	6 Months Ended	9 Months Ended	0 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	May 01, 2013	Dec. 29, 2012	May 31, 2009 Call option and warrant item	Sep. 28, 2013 Call option and warrant	Jun. 29, 2013 Warrant	Sep. 28, 2013 Warrant	May 01, 2013 Call options	May 01, 2013 Convertible senior notes	Sep. 28, 2013 Senior Unsecured Revolving Credit Facility	Oct. 04, 2013 Senior Unsecured Revolving Credit Facility Subsequent event
Debt
Senior unsecured revolving credit facility												$ 1,000,000,000
Portion available for issuance of letters of credit against facility												100,000,000
Term of debt instrument											4 years
Amount borrowed against facility											0
Amount paid to holders of notes in settlement of face value	215,000,000	2,000,000								215,000,000
Common stock issued to converting holders in settlement of the excess of the conversion value over the face value										8.9
Incremental net share settlement in excess of the face amount of the notes issued upon conversion of convertible notes, after giving effect to the exercise of the call options and warrants										7.4
Number of counterparties					2
Period for computing VWAP of common stock to determine settlement values								45 days
Common stock shares acquired upon settlement of call options									8.9
Common stock shares issued in connection with settlement of the warrants							7.4
Net increase in treasury stock due to settlement of call options and warrants						39,000,000
Common shares covered under capped call				28.7
Strike price of capped calls (in dollars per share)			$ 13.125
Cap price of capped calls (in dollars per share)			$ 15.75
Minimum Stock Price (in dollars per share)			$ 13.125
Maximum stock price (in dollars per share)			$ 15.75
Amount received from counterparties upon expiration of the capped calls			$ 75,000,000