Short-Term Borrowings and Long-Term Debt - Summary of Short-Term Capacities (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Schedule Of Borrowings [Line Items] | ||
| Total FHLB borrowing capacity | $ 7,165,149,000 | $ 8,854,696,000 |
| Unused federal funds lines available from commercial banks | 1,520,000,000 | 1,370,000,000 |
| Unused Federal Reserve borrowings capacity | 9,174,238,000 | 5,436,652,000 |
| Unused revolving line of credit | 75,000,000 | 75,000,000 |
| Borrowings | 0 | 0 |
| Loans | ||
| Schedule Of Borrowings [Line Items] | ||
| Total FHLB borrowing capacity | 2,570,596,000 | 4,664,703,000 |
| Debt Securities | ||
| Schedule Of Borrowings [Line Items] | ||
| Total FHLB borrowing capacity | $ 4,594,553,000 | $ 4,189,993,000 |