Repurchase of Common Stock (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended	3 Months Ended
		Jun. 05, 2018	May 05, 2018	Apr. 29, 2017	Mar. 01, 2018	Feb. 27, 2017	Jun. 30, 2011
Stock Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount					$ 1,500	$ 3,000
Total Share Repurchases [Domain]
Stock Repurchases [Line Items]
Stock Repurchased and Retired During Period, Value		$ 120
Stock Repurchased and Retired During Period, Shares		1.6
Adjusted Balance [Member]
Stock Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount					$ 3,500
Open market [Domain]
Stock Repurchases [Line Items]
Stock Repurchased and Retired During Period, Value	[1]		$ 399	$ 384
Average share price			$ 71.78	$ 46.30
Stock Repurchased and Retired During Period, Shares	[1]		5.6	8.3
Unsettled shares, cost			$ 12	$ 19
Unsettled shares, shares			0.2	0.3
February 2017 share repurchase program [Member]
Stock Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount						$ 5,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 2,600
June 2011 share repurchase program [Member}
Stock Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount							$ 5,000

[1] As of May 5, 2018, $12 million, or 0.2 million shares, in trades remained unsettled. As of April 29, 2017, $19 million, or 0.3 million shares, in trades remained unsettled. The liability for unsettled trades is included in Accrued liabilities on the Condensed Consolidated Balance Sheets.