Commitments and Contingencies - Commitments to Extend Credit on Lines of Credit and to Purchase First Mortgages (Details) - Residential real estate - USD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Total | $ 2,718 | $ 2,406 |
| Home Equity Loans and Lines of Credit, Pledged Asset Lines and Other Lines of Credit | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Commitments to extend credit related to unused HELOCs and other lines of credit | 1,793 | 1,895 |
| First Mortgages | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Commitments to purchase First Mortgage loans | $ 925 | $ 511 |