Investments - Summary of Selected Financial Information for Jefferies LoanCore (Detail) - Jefferies LoanCore, LLC [Member] - USD ($) $ in Millions	Feb. 28, 2017	Nov. 30, 2016
Schedule of Equity Method Investments [Line Items]
Total assets	$ 1,707.7	$ 1,827.2
Total liabilities	1,397.3	1,505.0
Total equity	310.4	322.2
Our total equity balance	$ 150.5	$ 156.3