Derivatives and Hedging Activities - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
|
| Derivative [Line Items] | |||||
| Notional Amount | $ 51,706.0 | $ 30,552.0 | $ 51,706.0 | $ 30,552.0 | $ 43,890.0 |
| Collateral posted by this counterparty | 399.0 | 130.0 | 399.0 | 130.0 | 117.0 |
| Designated as Hedging Instrument | |||||
| Derivative [Line Items] | |||||
| Notional Amount | 6,033.0 | 3,866.0 | 6,033.0 | 3,866.0 | 4,344.0 |
| Cumulative basis adjustment | 4.0 | 4.0 | 78.0 | ||
| Interest income related to amortization of cumulative basis adjustment (less than for current period) | (0.1) | $ 2.9 | (0.1) | $ 5.9 | |
| Designated as Hedging Instrument | Interest rate swap, terminated | |||||
| Derivative [Line Items] | |||||
| Notional Amount | 1,000.0 | 1,000.0 | |||
| Cumulative basis adjustment | (11.0) | (11.0) | |||
| Designated as Hedging Instrument | Portfolio layer method swaps | |||||
| Derivative [Line Items] | |||||
| Notional Amount | 500.0 | 500.0 | 500.0 | ||
| Cumulative basis adjustment | $ 1.0 | $ 1.0 | $ 4.0 | ||