Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Income taxes effect on net unrealized (losses) gains on securities available for sale	$ (18)	$ 33	$ 93	$ 35
Income taxes effect on net unrealized gains (losses) on derivative financial instruments	(24)	28	32	37
Income taxes effect on foreign currency translation adjustments	(1)	(3)	3	(11)
Income taxes effect on net pension and postretirement benefit costs	$ 1	$ (15)	$ 6	$ (12)