Variable Interest Entities - Variable Interests in Non-Consolidated Variable Interest Entities (Detail) - Variable Interest Entity Not Primary Beneficiary [Member] - USD ($) $ in Millions	Nov. 30, 2016	Nov. 30, 2015
Variable Interest Entity [Line Items]
Carrying Amount, Assets	$ 443.5	$ 352.5
Carrying Amount, Liabilities	4.8	0.2
Maximum exposure to loss	1,257.0	1,422.5
VIE Assets	9,467.5	11,981.9
Collateralized loan obligations [Member]
Variable Interest Entity [Line Items]
Carrying Amount, Assets	263.3	73.6
Carrying Amount, Liabilities	4.8	0.2
Maximum exposure to loss	920.0	458.1
VIE Assets	4,451.7	6,368.7
Consumer loan vehicles [Member]
Variable Interest Entity [Line Items]
Carrying Amount, Assets	90.3	188.3
Carrying Amount, Liabilities	0.0	0.0
Maximum exposure to loss	219.6	845.8
VIE Assets	985.5	1,133.0
Asset management vehicle [Member]
Variable Interest Entity [Line Items]
Carrying Amount, Assets	37.6	39.3
Carrying Amount, Liabilities	0.0	0.0
Maximum exposure to loss	63.6	65.8
VIE Assets	155.6	168.2
Private equity vehicles [Member]
Variable Interest Entity [Line Items]
Carrying Amount, Assets	52.3	51.3
Carrying Amount, Liabilities	0.0	0.0
Maximum exposure to loss	53.8	52.8
VIE Assets	$ 3,874.7	$ 4,312.0