Net Capital Requirements - Partnership's Net Capital Figures for U.S. and Canada Broker-Dealer Subsidiaries (Detail) - USD ($) $ in Millions	Jun. 29, 2018	Dec. 31, 2017
United States [Member]
Regulatory Capital Requirements
Net capital	$ 1,096	$ 1,107
Net capital in excess of the minimum required	$ 1,036	$ 1,049
Net capital as a percentage of aggregate debit items	36.70%	38.10%
Net capital after anticipated capital withdrawals, as a percentage of aggregate debit items	20.00%	21.60%
Canada [Member]
Regulatory Capital Requirements
Regulatory risk-adjusted capital	$ 42	$ 50
Regulatory risk-adjusted capital in excess of the minimum required to be held by IIROC	$ 37	$ 42