Expenses - Schedule of Expenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other Expenses [Abstract]
Professional services	$ 85	$ 89	$ 165	$ 168
Sales advertising public relations	27	29	54	55
Insurance	17	32	38	64
Regulatory fees and assessments	16	29	34	59
Bank operations	10	22	21	39
Other	119	94	237	190
Total other expenses	$ 274	$ 295	$ 549	$ 575