Investment Securities (Summary Of Agency Securities Estimated Weighted Average Life Classifications) (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Fair Value | $ 87,381 | $ 81,719 |
| Amortized Cost | $ 88,471 | $ 81,817 |
| Weighted Average Coupon | 5.05% | 5.19% |
| Weighted Average Yield | 4.91% | 4.93% |
| Less Than or Equal to Three Years [Member] | ||
| Fair Value | $ 1,219 | $ 4,670 |
| Amortized Cost | $ 1,206 | $ 4,630 |
| Weighted Average Coupon | 6.50% | 6.59% |
| Weighted Average Yield | 6.26% | 5.50% |
| Greater Than Three Years and Less Than or Equal to Five Years [Member] | ||
| Fair Value | $ 9,777 | $ 19,068 |
| Amortized Cost | $ 9,717 | $ 18,755 |
| Weighted Average Coupon | 5.84% | 5.85% |
| Weighted Average Yield | 5.40% | 5.50% |
| Greater Than Five Years [Member] | ||
| Fair Value | $ 71,237 | $ 55,562 |
| Amortized Cost | $ 72,417 | $ 56,048 |
| Weighted Average Coupon | 4.95% | 4.86% |
| Weighted Average Yield | 4.81% | 4.68% |
| Greater Than Ten Years [Member] | ||
| Fair Value | $ 5,148 | $ 2,419 |
| Amortized Cost | $ 5,131 | $ 2,384 |
| Weighted Average Coupon | 4.67% | 4.93% |
| Weighted Average Yield | 5.12% | 5.11% |