Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other Expenses [Abstract]
Professional services	$ 80	$ 81
Regulatory fees and assessments	18	12
Sales advertising public relations	17	18
Securities processing	12	15
Insurance	3	5
Bank operations	2	9
Other	90	90
Total other expenses	$ 222	$ 230