Variable Interest Entities - Unconsolidated LIHC Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Non Interest Expenses
Noncontrolling Interest [Line Items]
Losses from LIHC investments included in other noninterest expense	$ 1	$ 1	$ 2	$ 3
Income Tax Expense
Noncontrolling Interest [Line Items]
Amortization of LIHC investments included in income tax expense	28	30	59	64
Tax credits and other tax benefits from LIHC investments included in income tax expense	$ 43	$ 41	$ 79	$ 86