Variable Interest Entities - Assets and Liabilities of Consolidated VIEs Prior to Consolidation (Details) - USD ($) $ in Thousands	Feb. 28, 2021	Nov. 30, 2020
Variable Interest Entity [Line Items]
Assets	$ 51,386,411	$ 47,751,997
Liabilities	44,830,780	41,385,865
VIEs, primary beneficiary | Cash
Variable Interest Entity [Line Items]
VIE assets, eliminated in consolidation	1,200	700
VIEs, primary beneficiary | Other secured financings
Variable Interest Entity [Line Items]
VIE liabilities, eliminated in consolidation	131,200	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	3,934,300	2,908,900
Liabilities	3,934,300	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	3,934,300	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	3,933,200	2,907,800
VIEs, primary beneficiary | Secured Funding Vehicles | Other liabilities
Variable Interest Entity [Line Items]
Liabilities	1,100	1,100
VIEs, primary beneficiary | Other
Variable Interest Entity [Line Items]
Assets	45,200	19,400
Liabilities	9,900	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	12,600	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	31,200	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	9,400	2,500
VIEs, primary beneficiary | Other | Other secured financings
Variable Interest Entity [Line Items]
Liabilities	0	0
VIEs, primary beneficiary | Other | Other liabilities
Variable Interest Entity [Line Items]
Liabilities	$ 500	$ 400