Variable Interest Entities - Variable Interests in Non-Consolidated Variable Interest Entities (Details) - USD ($) $ in Thousands	May 31, 2020	Nov. 30, 2019
Variable Interest Entity [Line Items]
Assets	$ 45,084,417	$ 43,516,115
Liabilities	38,654,639	37,386,368
Nonconsolidated VIEs
Variable Interest Entity [Line Items]
Assets	1,191,300	938,000
Liabilities	0	600
Maximum Exposure to Loss	1,352,000	1,442,100
VIE Assets	20,068,300	16,373,900
Nonconsolidated VIEs | CLOs
Variable Interest Entity [Line Items]
Assets	64,900	152,600
Liabilities	0	600
Maximum Exposure to Loss	70,900	505,300
VIE Assets	5,874,800	7,845,000
Nonconsolidated VIEs | Consumer loan and other asset-backed vehicles
Variable Interest Entity [Line Items]
Assets	336,400	358,300
Liabilities	0	0
Maximum Exposure to Loss	472,900	490,600
VIE Assets	2,499,800	2,354,800
Nonconsolidated VIEs | Related party private equity vehicles
Variable Interest Entity [Line Items]
Assets	16,600	23,000
Liabilities	0	0
Maximum Exposure to Loss	27,700	34,300
VIE Assets	45,600	71,400
Nonconsolidated VIEs | Other investment vehicles
Variable Interest Entity [Line Items]
Assets	773,400	404,100
Liabilities	0	0
Maximum Exposure to Loss	780,500	411,900
VIE Assets	$ 11,648,100	$ 6,102,700