Revenues from Contracts with Customers (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended
	Feb. 29, 2020	Feb. 28, 2019
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 912,816	$ 570,000
Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	786,311	449,105
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	83,321	103,727
Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	43,184	17,168
Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	771,537	440,738
Reportable Segments | Investment Banking and Capital Markets | Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	649,069	323,389
Reportable Segments | Investment Banking and Capital Markets | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	79,438	100,205
Reportable Segments | Investment Banking and Capital Markets | Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	43,030	17,144
Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,091	8,318
Reportable Segments | Asset Management | Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,568	5,030
Reportable Segments | Asset Management | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,523	3,288
Reportable Segments | Asset Management | Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	135,293	121,136
Reportable Segments | Merchant Banking | Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	134,779	120,878
Reportable Segments | Merchant Banking | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	360	234
Reportable Segments | Merchant Banking | Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	154	24
Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Reportable Segments | Corporate | Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Reportable Segments | Corporate | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Reportable Segments | Corporate | Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(105)	(192)
Consolidation adjustments | Americas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(105)	(192)
Consolidation adjustments | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Consolidation adjustments | Asia
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Equities
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	176,144	151,882
Equities | Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	176,249	152,074
Equities | Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Equities | Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Equities | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Equities | Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(105)	(192)
Fixed Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,286	3,068
Fixed Income | Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,286	3,068
Fixed Income | Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Fixed Income | Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Fixed Income | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Fixed Income | Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Investment Banking - Underwriting
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	248,844	105,114
Investment Banking - Underwriting | Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	248,844	105,114
Investment Banking - Underwriting | Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Investment Banking - Underwriting | Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Investment Banking - Underwriting | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Investment Banking - Underwriting | Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Investment Banking - Advisory
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	343,158	180,482
Investment Banking - Advisory | Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	343,158	180,482
Investment Banking - Advisory | Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Investment Banking - Advisory | Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Investment Banking - Advisory | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Investment Banking - Advisory | Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,091	8,318
Asset Management | Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Asset Management | Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,091	8,318
Asset Management | Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Asset Management | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Asset Management | Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Manufacturing revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	77,607	75,425
Manufacturing revenues | Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Manufacturing revenues | Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Manufacturing revenues | Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	77,607	75,425
Manufacturing revenues | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Manufacturing revenues | Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Oil and gas revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	42,214	36,365
Oil and gas revenues | Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Oil and gas revenues | Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Oil and gas revenues | Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	42,214	36,365
Oil and gas revenues | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Oil and gas revenues | Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other revenues
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	15,472	9,346
Other revenues | Reportable Segments | Investment Banking and Capital Markets
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other revenues | Reportable Segments | Asset Management
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other revenues | Reportable Segments | Merchant Banking
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	15,472	9,346
Other revenues | Reportable Segments | Corporate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other revenues | Consolidation adjustments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 0	$ 0