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]	Stockholders' Equity, Total [Member]	Accelerated Share Repurchase Program [Member] Additional Paid-in Capital [Member]	Accelerated Share Repurchase Program [Member] Treasury Stock [Member]
Adjustments to Additional Paid in Capital [Abstract]
Additional Paid in Capital			$ 9,894
Retained Earnings (Accumulated Deficit) [Abstract]
Retained Earnings (Accumulated Deficit)				$ 10,683
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss), Net of Tax						$ (79)
Stock Repurchased During Period, Value								$ 131
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs			766
Adjustments to Additional Paid in Capital, Share-based Compensation, Employee Stock Purchase Program, Requisite Service Period Recognition			(52)
Allocated Share-based Compensation Expense	$ 64
Tax expense on employee stock options and awards			4
Net Income (Loss) Attributable to Parent	416			416
Dividends, Common Stock, Cash				213
Treasury Stock, Value at Dec. 31, 2013					$ (1,598)
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Treasury stock acquired					(971)				$ (394)
Issuance of shares under incentive and stock compensation plans from treasury stock					(65)
Return of shares under incentive and stock compensation plans and other to treasury stock	(12)				(14)
Treasury Stock, Value at Sep. 30, 2014					(2,146)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Net of Tax	1,156					1,156
Common Shares Outstanding, at beginning of period (in thousands) at Dec. 31, 2013		453,290.0
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Treasury stock acquired		(39,066.0)
Issuance of shares under incentive and stock compensation plans		1,562.0
Return of shares under incentive and stock compensation plans and other to treasury stock		(393.0)
Issuance of Shares for Warrant Exercise		18,177.0
Common Shares Outstanding, at end of period (in thousands) at Sep. 30, 2014		433,570.0
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Adjustments to Additional Paid in Capital, Stock Issued, Own-share Lending Arrangement, Issuance Costs					766
Common Stock, Value, Issued		$ 5
Additional Paid in Capital			9,013
Retained Earnings (Accumulated Deficit)				10,886
Accumulated Other Comprehensive Income (Loss), Net of Tax						1,077
Total stockholders' equity							$ 18,835
Common Stock, Value, Issued	5
Additional Paid in Capital	9,123		9,123
Retained Earnings (Accumulated Deficit)	11,191			11,191
Accumulated Other Comprehensive Income (Loss), Net of Tax	928					928
Total stockholders' equity	18,720
Stock Repurchased During Period, Value								$ 0
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs			87
Adjustments to Additional Paid in Capital, Share-based Compensation, Employee Stock Purchase Program, Requisite Service Period Recognition			(164)
Allocated Share-based Compensation Expense	57
Tax expense on employee stock options and awards			27
Net Income (Loss) Attributable to Parent	1,261			1,261
Dividends, Common Stock, Cash				237
Treasury Stock, Value at Dec. 31, 2014	(2,527)				(2,527)
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Treasury stock acquired					(800)				$ 0
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)
Treasury Stock, Value at Sep. 30, 2015	(3,112)				(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	(18.6)	(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
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Adjustments to Additional Paid in Capital, Stock Issued, Own-share Lending Arrangement, Issuance Costs					$ 87
Common Stock, Value, Issued	$ 5	$ 5
Additional Paid in Capital	8,956		$ 8,956
Retained Earnings (Accumulated Deficit)	12,215			$ 12,215
Accumulated Other Comprehensive Income (Loss), Net of Tax	140					$ 140
Total stockholders' equity	$ 18,204						$ 18,204