Net Capital Requirements - Partnership's Capital Figures for U.S. and Canada Broker-Dealer Subsidiaries (Detail) - USD ($) $ in Millions |
Sep. 25, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Canada [Member] | ||
| Regulatory Capital Requirements | ||
| Regulatory risk-adjusted capital | $ 126 | $ 102 |
| Regulatory risk-adjusted capital in excess of the minimum required | 125 | 101 |
| U.S. [Member] | ||
| Regulatory Capital Requirements | ||
| Net capital | 901 | 1,042 |
| Net capital in excess of the minimum required | $ 802 | $ 963 |
| Net capital as a percentage of aggregate debit items | 18.10% | 26.40% |
| Net capital after anticipated capital withdrawals, as a percentage of aggregate debit items | 4.40% | 9.50% |