Equity, Share Activity Rollforward (Details) - shares	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Share Activity
Treasury stock, shares, beginning balance	(200,462,208)
Treasury stock, shares, ending balance	(211,195,867)
Common Stock [Member]
Share Activity
Common stock, shares, beginning balance	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	(200,000,000)	(159,000,000)
Stock issuances, shares	1,000,000	2,000,000
Treasury stock, shares, ending balance	(211,000,000)	(174,000,000)
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	(11,000,000)	(15,000,000)