Variable Interest Entities Affordable Housing Tax Credits (Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - Low Income Housing Tax Credit Investments [Member] - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Variable Interest Entity [Line Items] | |||
| Tax credits and other tax benefits recognized | $ 165 | $ 174 | $ 189 |
| Tax credit amortization expense included in provision for income taxes | $ 131 | $ 137 | $ 160 |