Revenues from Contracts with Customers - Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended
	Feb. 28, 2018 USD ($)
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	$ 599,509
Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	594,579
Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	4,930
Americas
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	520,854
Americas | Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	515,924
Americas | Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	4,930
Europe
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	61,328
Europe | Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	61,328
Europe | Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	0
Asia
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	17,327
Asia | Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	17,327
Asia | Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	0
Equities (1)
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	151,630
Equities (1) | Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	151,630
Equities (1) | Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	0
Fixed Income (1)
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	2,958
Fixed Income (1) | Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	2,958
Fixed Income (1) | Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	0
Investment Banking - Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	248,834
Investment Banking - Capital Markets | Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	248,834
Investment Banking - Capital Markets | Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	0
Investment Banking - Advisory
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	191,157
Investment Banking - Advisory | Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	191,157
Investment Banking - Advisory | Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	0
Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	4,930
Asset Management | Capital Markets
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	0
Asset Management | Asset Management
Disaggregation Of Revenue [Line Items]
Revenues from contracts with customers	$ 4,930