Goodwill and Other Intangible Assets - Identifiable Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets
Servicing Asset at Fair Value, Amount	$ 159	$ 64
Amortization Expense	26	30	$ 28
Gross Carrying Amount	932	935
Accumulated Amortization	(647)	(622)
Net Carrying Amount	285	313
Core deposit intangibles
Intangible Assets
Gross Carrying Amount	565	565
Accumulated Amortization	(537)	(530)
Net Carrying Amount	28	35
Trade names
Intangible Assets
Gross Carrying Amount	111	113
Accumulated Amortization	(32)	(29)
Net Carrying Amount	79	84
Customer Relationships
Intangible Assets
Gross Carrying Amount	238	238
Accumulated Amortization	(63)	(47)
Net Carrying Amount	175	191
Other intangibles assets
Intangible Assets
Gross Carrying Amount	18	19
Accumulated Amortization	(15)	(16)
Net Carrying Amount	$ 3	$ 3