Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Receivables, allowances	$ 51	$ 53
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares issued	2,109,316,331	2,109,316,331
Repurchased stock, shares	544,554,521	520,313,919