Shareholders' Equity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Shareholders' equity activity [Roll Forward]
Balance at beginning of period		$ 13,615		$ 13,615	$ 15,790
Shares repurchased		(500)		(500)	(1,050)
Stock plans				357	244
Payments of dividends to shareholders				(254)	(231)
Other				(26)	(27)
Comprehensive income (loss)	775		649	1,395	639
Balance at end of period	14,587		15,365	14,587	15,365
Company shareholders' equity
Shareholders' equity activity [Roll Forward]
Balance at beginning of period		13,581		13,581	15,765
Shares repurchased					(1,050)
Stock plans				357	244
Payments of dividends to shareholders				(254)	(231)
Other				(22)	(24)
Comprehensive income (loss)				1,400	633
Balance at end of period	14,562		15,337	14,562	15,337
Noncontrolling interest in consolidated subsidiaries
Shareholders' equity activity [Roll Forward]
Balance at beginning of period		34		34	25
Shares repurchased				0	0
Stock plans				0	0
Payments of dividends to shareholders				0	0
Other				(4)	(3)
Comprehensive income (loss)				(5)	6
Balance at end of period	$ 25		$ 28	$ 25	$ 28