Variable Interest Entities - Variable Interests in Non-Consolidated Variable Interest Entities (Detail) - Nonconsolidated VIEs - USD ($) $ in Millions	May 31, 2019	Nov. 30, 2018
Variable Interest Entity [Line Items]
Carrying Amount, Assets	$ 966.6	$ 634.7
Carrying Amount, Liabilities	0.6	0.0
Maximum Exposure to Loss	1,856.5	1,528.0
VIE Assets	17,202.1	10,028.4
CLOs
Variable Interest Entity [Line Items]
Carrying Amount, Assets	111.7	42.1
Carrying Amount, Liabilities	0.6	0.0
Maximum Exposure to Loss	827.5	568.3
VIE Assets	7,806.3	3,088.9
Consumer loan and other asset-backed vehicles
Variable Interest Entity [Line Items]
Carrying Amount, Assets	427.3	462.1
Carrying Amount, Liabilities	0.0	0.0
Maximum Exposure to Loss	570.1	807.1
VIE Assets	3,322.6	3,273.1
Related party private equity vehicles
Variable Interest Entity [Line Items]
Carrying Amount, Assets	31.2	35.5
Carrying Amount, Liabilities	0.0	0.0
Maximum Exposure to Loss	49.0	53.5
VIE Assets	92.0	108.3
Other investment vehicles
Variable Interest Entity [Line Items]
Carrying Amount, Assets	396.4	95.0
Carrying Amount, Liabilities	0.0	0.0
Maximum Exposure to Loss	409.9	99.1
VIE Assets	$ 5,981.2	$ 3,558.1