Condensed Consolidated Statements of Changes in Stockholders' Equity Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stocks	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Adjustments to Additional Paid in Capital [Abstract]
Additional Paid in Capital			$ 9,123
Retained Earnings (Accumulated Deficit) [Abstract]
Retained Earnings (Accumulated Deficit)				$ 11,191
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Net of Tax						$ 928
Adjustments to Additional Paid in Capital, Share-based Compensation, Employee Stock Purchase Program, Requisite Service Period Recognition			(164)
Allocated Share-based Compensation Expense			57
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation			27
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs			87
Net Income (Loss) Attributable to Parent	$ 1,261			1,261
Dividends, Common Stock, Cash				237
Treasury Stock, Value at Dec. 31, 2014					$ (2,527)
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Treasury stock acquired					(800)
Issuance of shares under incentive and stock compensation plans from treasury stock					(182)
Return of shares under incentive and stock compensation plans and other to treasury stock	(40)				(54)
Adjustments to Additional Paid in Capital, Stock Issued, Own-share Lending Arrangement, Issuance Costs					87
Treasury Stock, Value at Sep. 30, 2015					(3,112)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Net of Tax	(788)					(788)
Common Shares Outstanding, at beginning of period (in thousands) at Dec. 31, 2014		424,416.0
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Treasury stock acquired		(18,625.0)
Issuance of shares under incentive and stock compensation plans		4,617.0
Return of shares under incentive and stock compensation plans and other to treasury stock		(1,306.0)
Issuance of Shares for Warrant Exercise		2,212.0
Common Shares Outstanding, at end of period (in thousands) at Sep. 30, 2015		411,314.0
Adjustments to Additional Paid in Capital [Abstract]
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation			0
Treasury Stock, Value at Dec. 31, 2014					(2,527)
Treasury Stock, Value at Dec. 31, 2015	(3,557)				(3,557)
Common Shares Outstanding, at beginning of period (in thousands) at Dec. 31, 2014		424,416.0
Common Shares Outstanding, at end of period (in thousands) at Dec. 31, 2015		401,821.0
Preferred Stock, Including Additional Paid in Capital [Abstract]
Common Stock, Value, Issued		$ 5
Adjustments to Additional Paid in Capital [Abstract]
Additional Paid in Capital			8,956
Retained Earnings (Accumulated Deficit) [Abstract]
Retained Earnings (Accumulated Deficit)				12,215
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Net of Tax						140
Total stockholders' equity	18,204
Common Stock, Value, Issued	5
Additional Paid in Capital	8,973		8,973
Retained Earnings (Accumulated Deficit)	12,550			12,550
Accumulated Other Comprehensive Income (Loss), Net of Tax	(329)					(329)
Total stockholders' equity	17,642
Adjustments to Additional Paid in Capital, Share-based Compensation, Employee Stock Purchase Program, Requisite Service Period Recognition			(129)
Allocated Share-based Compensation Expense			58
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation			2
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs			11
Net Income (Loss) Attributable to Parent	977			977
Dividends, Common Stock, Cash				245
Treasury stock acquired					(1,050)
Issuance of shares under incentive and stock compensation plans from treasury stock					(134)
Return of shares under incentive and stock compensation plans and other to treasury stock	(10)				(47)
Adjustments to Additional Paid in Capital, Stock Issued, Own-share Lending Arrangement, Issuance Costs					11
Treasury Stock, Value at Sep. 30, 2016	(4,509)				$ (4,509)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Net of Tax	$ 1,316					1,316
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Treasury stock acquired	(24.6)	(24,652.0)
Issuance of shares under incentive and stock compensation plans		3,297.0
Return of shares under incentive and stock compensation plans and other to treasury stock		(1,091.0)
Issuance of Shares for Warrant Exercise		273.0
Common Shares Outstanding, at end of period (in thousands) at Sep. 30, 2016		379,648.0
Preferred Stock, Including Additional Paid in Capital [Abstract]
Common Stock, Value, Issued	$ 5	$ 5
Adjustments to Additional Paid in Capital [Abstract]
Additional Paid in Capital	8,893		$ 8,893
Retained Earnings (Accumulated Deficit) [Abstract]
Retained Earnings (Accumulated Deficit)	13,282			$ 13,282
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Net of Tax	987					$ 987
Total stockholders' equity	$ 18,658