Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) - USD ($) $ in Millions |
Mar. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Fair Value | $ 71,325 | $ 66,348 |
| Amortized Cost | $ 73,148 | $ 69,446 |
| Weighted Average Coupon | 5.12% | 5.03% |
| Weighted Average Yield | 4.87% | 4.77% |
| Less Than or Equal to Three Years [Member] | ||
| Fair Value | $ 536 | $ 539 |
| Amortized Cost | $ 548 | $ 530 |
| Weighted Average Coupon | 7.31% | 7.37% |
| Weighted Average Yield | 7.14% | 8.06% |
| Greater Than Three Years and Less Than or Equal to Five Years [Member] | ||
| Fair Value | $ 5,660 | $ 2,026 |
| Amortized Cost | $ 5,611 | $ 2,066 |
| Weighted Average Coupon | 6.21% | 5.96% |
| Weighted Average Yield | 5.74% | 5.48% |
| Greater Than Five Years [Member] | ||
| Fair Value | $ 61,379 | $ 56,551 |
| Amortized Cost | $ 63,212 | $ 59,479 |
| Weighted Average Coupon | 5.00% | 4.97% |
| Weighted Average Yield | 4.75% | 4.66% |
| Greater Than Ten Years [Member] | ||
| Fair Value | $ 3,750 | $ 7,232 |
| Amortized Cost | $ 3,777 | $ 7,371 |
| Weighted Average Coupon | 5.24% | 5.14% |
| Weighted Average Yield | 5.21% | 5.24% |