Equity, Share Activity Rollforward (Details) - shares	1 Months Ended	9 Months Ended
	Oct. 31, 2015	Sep. 30, 2016	Sep. 30, 2015
Share Activity
Treasury stock, shares, beginning balance		(200,462,208)
Stock purchases, shares	(506,100)
Treasury stock, shares, ending balance		(220,417,088)
Common Stock [Member]
Share Activity
Common stock, shares, beginning balance	673,000,000	673,000,000	673,000,000
Stock issuances, shares		0	0
Common stock, shares, ending balance		673,000,000	673,000,000
Treasury Stock [Member]
Share Activity
Treasury stock, shares, beginning balance	(190,000,000)	(200,000,000)	(159,000,000)
Stock issuances, shares		1,000,000	3,000,000
Treasury stock, shares, ending balance		(220,000,000)	(190,000,000)
Treasury Stock [Member] | Stock-Based Compensation Plans Purchase Program [Member]
Share Activity
Stock purchases, shares		(1,000,000)	(2,000,000)
Treasury Stock [Member] | Common Stock Purchase Program [Member]
Share Activity
Stock purchases, shares		(20,000,000)	(32,000,000)