Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Expenses [Abstract]
Professional services	$ 89	$ 70	$ 261	$ 235
Sales advertising public relations	20	30	50	83
Regulatory fees and assessments	16	19	45	55
Securities processing	10	27	40	54
Bank operations	2	10	15	30
Insurance	2	5	10	14
Other	90	107	281	346
Total other expenses	$ 229	$ 268	$ 702	$ 817