Collateralized Transactions - Summary of Repurchase Agreements and Securities Borrowing and Lending Arrangements (Footnote) (Detail) - USD ($) $ in Millions	Nov. 30, 2017	Nov. 30, 2016
Banking and Thrift [Abstract]
Securities borrowing arrangements	$ 5,678.6	$ 6,337.5
Securities borrowing arrangements, collateral	5,516.7	6,146.0
Securities borrowing arrangements, repurchase agreements	1,084.4	810.4
Securities borrowing arrangements, pledged securities collateral	$ 1,115.9	$ 834.2