Collateralized Transactions - Summary of Repurchase Agreements and Securities Borrowing and Lending Arrangements (Footnote) (Detail) - USD ($) $ in Millions	May. 31, 2015	Nov. 30, 2014
Banking and Thrift [Abstract]
Securities borrowing arrangements	$ 6,327.5	$ 4,847.4
Securities borrowing arrangements, collateral	6,143.2	4,694.0
Securities borrowing arrangements, repurchase agreements	1,750.5	1,201.9
Securities borrowing arrangements, pledged securities collateral	$ 1,802.5	$ 1,238.4