Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other Expenses [Abstract]
Litigation	$ 47	$ (7)	$ 47	$ 396
Insurance	31	33	74	98
Regulatory fees and assessments	28	31	65	90
Securities processing	10	40	20	75
Other	71	44	231	186
Total other expenses	$ 187	$ 141	$ 437	$ 845