Variable Interest Entities (Schedule of Consolidated VIEs) (Details) - USD ($) $ in Thousands		Aug. 31, 2020	Nov. 30, 2019
Variable Interest Entity [Line Items]
Assets	[1]	$ 51,773,988	$ 49,460,234
Liabilities	[1]	42,180,264	39,706,945
Variable interest entities, primary beneficiary
Variable Interest Entity [Line Items]
Assets		637,500	645,800
Liabilities		3,377,300	3,071,100
Variable interest entities, primary beneficiary | Cash
Variable Interest Entity [Line Items]
VIE assets, eliminated in consolidation		600
Variable interest entities, primary beneficiary | Other secured financings
Variable Interest Entity [Line Items]
VIE liabilities, eliminated in consolidation		130,100
Variable interest entities, primary beneficiary | Other liabilities
Variable Interest Entity [Line Items]
VIE liabilities, eliminated in consolidation		1,800	17,900
Variable interest entities, primary beneficiary | Secured Funding Vehicles
Variable Interest Entity [Line Items]
Assets		3,539,500	3,111,600
Liabilities		3,506,600	3,088,700
Variable interest entities, primary beneficiary | Secured Funding Vehicles | Cash
Variable Interest Entity [Line Items]
Assets		0	0
Variable interest entities, primary beneficiary | Secured Funding Vehicles | Financial instruments owned, at fair value
Variable Interest Entity [Line Items]
Assets		0	0
Variable interest entities, primary beneficiary | Secured Funding Vehicles | Securities purchased under agreements to resell
Variable Interest Entity [Line Items]
Assets		2,919,800	2,467,300
Variable interest entities, primary beneficiary | Secured Funding Vehicles | Receivables
Variable Interest Entity [Line Items]
Assets		581,900	605,600
Variable interest entities, primary beneficiary | Secured Funding Vehicles | Other
Variable Interest Entity [Line Items]
Assets		37,800	38,700
Variable interest entities, primary beneficiary | Secured Funding Vehicles | Financial instruments sold, not yet purchased, at fair value
Variable Interest Entity [Line Items]
Liabilities		0	0
Variable interest entities, primary beneficiary | Secured Funding Vehicles | Other secured financings
Variable Interest Entity [Line Items]
Liabilities		3,502,900	3,068,600
Variable interest entities, primary beneficiary | Secured Funding Vehicles | Other liabilities
Variable Interest Entity [Line Items]
Liabilities		3,700	20,100
Variable interest entities, primary beneficiary | Other
Variable Interest Entity [Line Items]
Assets		18,400	1,500
Liabilities		2,500	200
Variable interest entities, primary beneficiary | Other | Cash
Variable Interest Entity [Line Items]
Assets		1,200	1,200
Variable interest entities, primary beneficiary | Other | Financial instruments owned, at fair value
Variable Interest Entity [Line Items]
Assets		3,600	300
Variable interest entities, primary beneficiary | Other | Securities purchased under agreements to resell
Variable Interest Entity [Line Items]
Assets		0	0
Variable interest entities, primary beneficiary | Other | Receivables
Variable Interest Entity [Line Items]
Assets		13,500	0
Variable interest entities, primary beneficiary | Other | Other
Variable Interest Entity [Line Items]
Assets		100	0
Variable interest entities, primary beneficiary | Other | Financial instruments sold, not yet purchased, at fair value
Variable Interest Entity [Line Items]
Liabilities		2,100	0
Variable interest entities, primary beneficiary | Other | Other secured financings
Variable Interest Entity [Line Items]
Liabilities		0	0
Variable interest entities, primary beneficiary | Other | Other liabilities
Variable Interest Entity [Line Items]
Liabilities		$ 400	$ 200

[1] Total assets include assets related to variable interest entities of $637.5 million and $645.8 million at August 31, 2020 and November 30, 2019, respectively, and Total liabilities include liabilities related to variable interest entities of $3,377.3 million and $3,071.1 million at August 31, 2020 and November 30, 2019, respectively. See Note 7 for additional information related to variable interest entities.