Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Expenses [Abstract]
Professional services	$ 91	$ 85	$ 172	$ 165
Regulatory fees and assessments	17	16	29	36
Securities processing	15	19	30	28
Sales advertising public relations	12	27	30	54
Bank operations	4	10	13	21
Insurance	3	4	8	9
Other	101	113	191	236
Total other expenses	$ 243	$ 274	$ 473	$ 549