Derivative Instruments and Other Financial Instruments Used For Hedging - Schedule of Derivative Gains (Losses) on the Company's Fair Value Hedges (Details) - Fair value hedges - Interest rate derivative contracts - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Amount and location of net gains and losses
Derivative	$ (1)	$ (4)	$ (2)	$ 5
Hedged Item	1	4	1	(5)
Hedge Ineffectiveness	0	0	(1)	0
Designated as Hedging Instrument
Amount and location of net gains and losses
Derivative	(1)	(4)	(2)	5
Hedged Item	1	4	1	(5)
Hedge Ineffectiveness	$ 0	$ 0	$ (1)	$ 0