Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Other Expenses [Abstract]
Insurance	$ 22	$ 37
Regulatory fees and assessments	20	34
Securities processing	4	20
Litigation	0	150
Other	66	60
Total other expenses	$ 112	$ 301