Shareholders' Equity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Shareholders' equity activity [Roll Forward]
Balance at beginning of period	$ 13,615	$ 15,790
Shares repurchased	(500)	(50)
Stock plans	146	128
Payments of dividends to shareholders	(127)	(116)
Other	(2)	(5)
Comprehensive income (loss)	620	(10)
Balance at end of period	13,752	15,737
Company shareholders' equity
Shareholders' equity activity [Roll Forward]
Balance at beginning of period	13,581	15,765
Stock plans	146	128
Payments of dividends to shareholders	(127)	(116)
Other	(1)	(4)
Comprehensive income (loss)	626	(13)
Balance at end of period	13,725	15,710
Noncontrolling interest in consolidated subsidiaries
Shareholders' equity activity [Roll Forward]
Balance at beginning of period	34	25
Shares repurchased	0	0
Stock plans	0	0
Payments of dividends to shareholders	0	0
Other	(1)	(1)
Comprehensive income (loss)	(6)	3
Balance at end of period	$ 27	$ 27