Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Millions |
Jun. 30, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Finite-Lived Intangible Assets | ||
| Gross Carrying Amount | $ 270 | $ 273 |
| Accumulated Amortization | (153) | (134) |
| Net Carrying Amount | 117 | 139 |
| Core deposit intangibles | ||
| Finite-Lived Intangible Assets | ||
| Gross Carrying Amount | 229 | 229 |
| Accumulated Amortization | (135) | (116) |
| Net Carrying Amount | 94 | 113 |
| Customer relationships | ||
| Finite-Lived Intangible Assets | ||
| Gross Carrying Amount | 24 | 24 |
| Accumulated Amortization | (6) | (5) |
| Net Carrying Amount | 18 | 19 |
| Operating leases | ||
| Finite-Lived Intangible Assets | ||
| Gross Carrying Amount | 14 | 17 |
| Accumulated Amortization | (11) | (12) |
| Net Carrying Amount | 3 | 5 |
| Other | ||
| Finite-Lived Intangible Assets | ||
| Gross Carrying Amount | 3 | 3 |
| Accumulated Amortization | (1) | (1) |
| Net Carrying Amount | $ 2 | $ 2 |