CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net unrealized derivative instrument gains arising during the periods, tax	$ 8	$ (3)	$ 29	$ 36
Reclassification adjustment for net derivative gains included in net income, tax	(4)	(1)	(10)	(2)
Net unrealized securities available for sale gains arising during the periods, tax	39	(66)	131	(12)
Other-than-temporary impairment not recognized in earnings on securities, tax	2	0	(13)	(11)
Reclassification of net securities gains to net income, tax	1	(2)	(2)	(5)
Amortization of actuarial loss, tax	$ 1	$ 2	$ 3	$ 3