Net Capital Requirements - Partnership's Net Capital Figures for U.S. and Canada Broker-Dealer Subsidiaries (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
United States [Member]
Regulatory Capital Requirements
Net capital	$ 974	$ 998
Net capital in excess of the minimum required	$ 918	$ 941
Net capital as a percentage of aggregate debit items	34.70%	35.00%
Net capital after anticipated capital withdrawals, as a percentage of aggregate debit items	22.60%	23.10%
Canada [Member]
Regulatory Capital Requirements
Regulatory risk adjusted capital	$ 33	$ 37
Regulatory risk adjusted capital in excess of the minimum required to be held by IIROC	$ 27	$ 33

Capital in excess required to be held by investment industry regulatory organization of foreign country.

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- Definition

Foreign country brokers dealers regulatory risk adjusted capital.

+ References

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- Definition

Net capital after anticipated capital withdrawals to aggregate debit items percentage.

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- Definition

Net capital to aggregate debit item percentage.

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- Definition

The amount of net capital in excess of the alternative minimum required net capital.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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- Definition

Net capital is equal to the net worth of the broker dealer, less certain items such as exchange memberships, carrying value of securities not readily marketable, haircuts on marketable securities in proprietary accounts, furniture and equipment and other illiquid assets as defined.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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