Schedule I - Condensed Statements of Financial Condition (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
ASSETS:
Cash and cash equivalents	$ 937	$ 1,033	$ 600	$ 601
Investment securities	201	161
Other assets	128	128
TOTAL ASSETS	16,356	14,770	13,795
LIABILITIES:
Accounts payable and accrued expenses	182	164
Partnership capital subject to mandatory redemption	2,610	2,218	2,081	1,983
TOTAL LIABILITIES	16,356	14,770
Parent Company [Member]
ASSETS:
Cash and cash equivalents	331	119	$ 252	$ 285
Investment securities	9	9
Investment in subsidiaries	2,255	2,076
Other assets	15	15
TOTAL ASSETS	2,610	2,219
LIABILITIES:
Accounts payable and accrued expenses		1
Partnership capital subject to mandatory redemption	2,610	2,218
TOTAL LIABILITIES	$ 2,610	$ 2,219