Variable Interest Entities - Variable Interests in Non-Consolidated Variable Interest Entities (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
Nonconsolidated VIEs
Variable Interest Entity [Line Items]
Assets	1,140,400	938,000
Liabilities	1,400	600
Maximum Exposure to Loss	1,688,800	1,442,100
VIE Assets	22,117,600	16,373,900
Nonconsolidated VIEs | CLOs
Variable Interest Entity [Line Items]
Assets	66,300	152,600
Liabilities	1,400	600
Maximum Exposure to Loss	470,400	505,300
VIE Assets	6,509,500	7,845,000
Nonconsolidated VIEs | Consumer loan and other asset-backed vehicles
Variable Interest Entity [Line Items]
Assets	308,400	358,300
Liabilities	0	0
Maximum Exposure to Loss	435,000	490,600
VIE Assets	2,300,400	2,354,800
Nonconsolidated VIEs | Related party private equity vehicles
Variable Interest Entity [Line Items]
Assets	18,600	23,000
Liabilities	0	0
Maximum Exposure to Loss	29,600	34,300
VIE Assets	50,700	71,400
Nonconsolidated VIEs | Other investment vehicles
Variable Interest Entity [Line Items]
Assets	747,100	404,100
Liabilities	0	0
Maximum Exposure to Loss	753,800	411,900
VIE Assets	$ 13,257,000	$ 6,102,700