Consolidated Statement of Changes In Shareholders' Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (USD per share)	$ 1.32	$ 1.16	$ 1.04
Common stock awards and options exercised, related taxes	$ 70	$ 72	$ 51