Variable Interest Entities - Assets and Liabilities of Consolidated VIEs Prior to Consolidation (Details) - USD ($) $ in Thousands	May 31, 2021	Nov. 30, 2020
Variable Interest Entity [Line Items]
Assets	$ 52,171,073	$ 47,751,997
Liabilities	45,483,725	41,385,865
VIEs, primary beneficiary | Cash
Variable Interest Entity [Line Items]
VIE assets, eliminated in consolidation	1,200	700
VIEs, primary beneficiary | Financial instruments owned
Variable Interest Entity [Line Items]
VIE assets, eliminated in consolidation	200
VIEs, primary beneficiary | Other secured financings
Variable Interest Entity [Line Items]
VIE liabilities, eliminated in consolidation		138,200
VIEs, primary beneficiary | Other liabilities
Variable Interest Entity [Line Items]
VIE liabilities, eliminated in consolidation	300	300
VIEs, primary beneficiary | Secured Funding Vehicles
Variable Interest Entity [Line Items]
Assets	3,535,200	2,908,900
Liabilities	3,535,200	2,908,900
VIEs, primary beneficiary | Secured Funding Vehicles | Cash
Variable Interest Entity [Line Items]
Assets	0	0
VIEs, primary beneficiary | Secured Funding Vehicles | Financial instruments owned
Variable Interest Entity [Line Items]
Assets	0	0
VIEs, primary beneficiary | Secured Funding Vehicles | Securities purchased under agreement to resell
Variable Interest Entity [Line Items]
Assets	3,535,200	2,908,900
VIEs, primary beneficiary | Secured Funding Vehicles | Receivable from brokers
Variable Interest Entity [Line Items]
Assets	0	0
VIEs, primary beneficiary | Secured Funding Vehicles | Other assets
Variable Interest Entity [Line Items]
Assets	0	0
VIEs, primary beneficiary | Secured Funding Vehicles | Financial instruments sold, not yet purchased
Variable Interest Entity [Line Items]
Liabilities	0	0
VIEs, primary beneficiary | Secured Funding Vehicles | Other secured financings
Variable Interest Entity [Line Items]
Liabilities	3,533,800	2,907,800
VIEs, primary beneficiary | Secured Funding Vehicles | Payables to customers
Variable Interest Entity [Line Items]
Liabilities	0	0
VIEs, primary beneficiary | Secured Funding Vehicles | Other liabilities
Variable Interest Entity [Line Items]
Liabilities	1,400	1,100
VIEs, primary beneficiary | Other
Variable Interest Entity [Line Items]
Assets	24,100	19,400
Liabilities	800	2,900
VIEs, primary beneficiary | Other | Cash
Variable Interest Entity [Line Items]
Assets	1,200	1,200
VIEs, primary beneficiary | Other | Financial instruments owned
Variable Interest Entity [Line Items]
Assets	200	5,200
VIEs, primary beneficiary | Other | Securities purchased under agreement to resell
Variable Interest Entity [Line Items]
Assets	0	0
VIEs, primary beneficiary | Other | Receivable from brokers
Variable Interest Entity [Line Items]
Assets	22,500	12,900
VIEs, primary beneficiary | Other | Other assets
Variable Interest Entity [Line Items]
Assets	200	100
VIEs, primary beneficiary | Other | Financial instruments sold, not yet purchased
Variable Interest Entity [Line Items]
Liabilities	0	2,500
VIEs, primary beneficiary | Other | Other secured financings
Variable Interest Entity [Line Items]
Liabilities	0	0
VIEs, primary beneficiary | Other | Payables to customers
Variable Interest Entity [Line Items]
Liabilities	300	0
VIEs, primary beneficiary | Other | Other liabilities
Variable Interest Entity [Line Items]
Liabilities	$ 500	$ 400