Variable Interest Entities - Assets and Liabilities of Consolidated VIEs Prior to Consolidation (Details) - USD ($) $ in Thousands	Feb. 29, 2020	Nov. 30, 2019
Variable Interest Entity [Line Items]
Assets	$ 46,202,597	$ 43,516,115
Liabilities	39,870,148	37,386,368
VIEs, primary beneficiary | Securities purchased under agreement to resell
Variable Interest Entity [Line Items]
VIE assets, not eliminated in consolidation	115,400
VIEs, primary beneficiary | Other liabilities
Variable Interest Entity [Line Items]
VIE liabilities, eliminated in consolidation	200	200
VIEs, primary beneficiary | Secured Funding Vehicles
Variable Interest Entity [Line Items]
Assets	2,166,900	2,467,300
Liabilities	2,166,900	2,467,300
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	2,166,900	2,467,300
VIEs, primary beneficiary | Secured Funding Vehicles | Receivable from brokers
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
VIEs, primary beneficiary | Secured Funding Vehicles | Other secured financings
Variable Interest Entity [Line Items]
Liabilities	2,165,500	2,465,800
VIEs, primary beneficiary | Secured Funding Vehicles | Other liabilities
Variable Interest Entity [Line Items]
Liabilities	1,400	1,500
VIEs, primary beneficiary | Other
Variable Interest Entity [Line Items]
Assets	21,300	1,500
Liabilities	4,500	200
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	3,900	300
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	16,200	0
VIEs, primary beneficiary | Other | Financial instruments sold, not yet purchased
Variable Interest Entity [Line Items]
Liabilities	4,200
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	$ 300	$ 200