Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Unrecognized amounts on retirement benefits, tax	$ 7	$ 13	$ 4	$ 13
Unrealized (losses) gains on available-for-sale securities, tax	(69)	79	121	158
Unrealized (losses) gains on cash flow hedges, tax	$ (6)	$ (5)	$ (9)	$ 8