Collateralized Transactions - Summary of Repurchase Agreements and Securities Borrowing and Lending Arrangements (Footnote) (Detail) - USD ($) $ in Millions	Aug. 31, 2017	Nov. 30, 2016
Banking and Thrift [Abstract]
Securities borrowing arrangements	$ 6,088.9	$ 6,337.5
Securities borrowing arrangements, collateral	5,942.3	6,146.0
Securities borrowing arrangements, repurchase agreements	887.2	810.4
Securities borrowing arrangements, repurchase agreements, pledged securities collateral	$ 908.8	$ 834.2