AFS and HTM Debt Securities, HTM Debt Securities Purchases (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Debt Securities, Held-to-maturity Purchase or Transfer of Investment [Abstract] | ||
| Purchases of held-to-maturity debt securities | $ 35 | $ 86 |
| AFS and HTM Debt Securities Textual [Abstract] | ||
| Transfers to held-to-maturity debt securities | 0 | 0 |
| Non-agency mortgage-backed securities [Member] | ||
| Debt Securities, Held-to-maturity Purchase or Transfer of Investment [Abstract] | ||
| Purchases of held-to-maturity debt securities | $ 35 | $ 86 |