Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Expenses [Abstract]
Professional services	$ 81	$ 80
Sales advertising public relations	18	27
Securities processing	15	9
Regulatory fees and assessments	12	20
Bank operations	9	11
Insurance	5	5
Other	90	123
Total other expenses	$ 230	$ 275