Variable Interest Entities - Assets and Liabilities of Consolidated VIEs Prior to Consolidation (Details) - USD ($) $ in Thousands	Aug. 31, 2020	Nov. 30, 2019
Variable Interest Entity [Line Items]
Assets	$ 46,660,448	$ 43,516,115
Liabilities	40,155,994	37,386,368
Secured Funding Vehicles | Other assets
Variable Interest Entity [Line Items]
Assets		0
Other | Other assets
Variable Interest Entity [Line Items]
Assets	100
VIEs, primary beneficiary | Cash
Variable Interest Entity [Line Items]
VIE assets, eliminated in consolidation	600
VIEs, primary beneficiary | Other secured financings
Variable Interest Entity [Line Items]
VIE liabilities, eliminated in consolidation	130,100
VIEs, primary beneficiary | Other liabilities
Variable Interest Entity [Line Items]
VIE liabilities, eliminated in consolidation	300	200
VIEs, primary beneficiary | Secured Funding Vehicles
Variable Interest Entity [Line Items]
Assets	2,919,800	2,467,300
Liabilities	2,919,800	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	2,919,800	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 | Other assets
Variable Interest Entity [Line Items]
Assets	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	2,918,400	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	18,400	1,500
Liabilities	2,500	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	3,600	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	13,500	0
VIEs, primary beneficiary | Other | Other assets
Variable Interest Entity [Line Items]
Assets		0
VIEs, primary beneficiary | Other | Financial instruments sold, not yet purchased
Variable Interest Entity [Line Items]
Liabilities	2,100	0
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	$ 400	$ 200