Schedule I - Condensed Statements of Financial Condition (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
ASSETS:
Cash and cash equivalents	$ 1,047	$ 937	$ 1,033	$ 600
Investment securities	224	201
Other assets	128	128
TOTAL ASSETS	19,424	16,356	14,770
LIABILITIES:
Partnership capital subject to mandatory redemption	2,634	2,610	2,218	2,081
TOTAL LIABILITIES	19,424	16,356
Parent Company [Member]
ASSETS:
Cash and cash equivalents	456	331	$ 119	$ 252
Investment securities	9	9
Investment in subsidiaries	2,150	2,255
Other assets	19	15
TOTAL ASSETS	2,634	2,610
LIABILITIES:
Partnership capital subject to mandatory redemption	2,634	2,610
TOTAL LIABILITIES	$ 2,634	$ 2,610