Derivative Instruments and Hedging Activities - Notional Amounts of Derivative Positions (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Derivative [Line Items] | ||||
| Average notional amount | $ 9,870,332 | $ 18,778,774 | $ 11,755,121 | $ 19,580,828 |
| Inverse interest-only securities | ||||
| Derivative [Line Items] | ||||
| Average notional amount | 1,049,640 | 725,242 | 1,129,186 | 446,686 |
| Interest rate swap agreements | ||||
| Derivative [Line Items] | ||||
| Average notional amount | 11,605,244 | 19,062,123 | 12,434,570 | 19,728,068 |
| TBAs, net | ||||
| Derivative [Line Items] | ||||
| Average notional amount | 3,191,563 | 2,471,752 | 3,507,992 | 2,794,246 |
| Futures, net | ||||
| Derivative [Line Items] | ||||
| Average notional amount | 6,026,500 | 3,518,726 | 5,376,000 | 3,434,363 |
| Interest rate lock commitments | ||||
| Derivative [Line Items] | ||||
| Average notional amount | 50,385 | 33,461 | 59,373 | 31,194 |
| Forward mortgage loan sale commitments | ||||
| Derivative [Line Items] | ||||
| Average notional amount | $ 0 | $ 4,922 | $ 0 | $ 14,997 |