Variable Interest Entities - Variable Interests in Non-Consolidated Variable Interest Entities (Detail) - Variable Interest Entity Not Primary Beneficiary [Member] - USD ($) $ in Millions	Nov. 30, 2015	Nov. 30, 2014
Variable Interest Entity [Line Items]
Carrying Amount, Assets	$ 289.7	$ 360.2
Carrying Amount, Liabilities	0.2	0.0
Maximum exposure to loss	1,345.1	1,795.2
VIE Assets	7,628.0	8,747.4
Collateralized loan obligations [Member]
Variable Interest Entity [Line Items]
Carrying Amount, Assets	73.6	134.0
Carrying Amount, Liabilities	0.2	0.0
Maximum exposure to loss	458.1	926.9
VIE Assets	6,368.7	7,737.1
Consumer loan vehicles [Member]
Variable Interest Entity [Line Items]
Carrying Amount, Assets	188.3	170.6
Carrying Amount, Liabilities	0.0	0.0
Maximum exposure to loss	845.8	797.8
VIE Assets	1,133.0	485.2
Asset management vehicle [Member]
Variable Interest Entity [Line Items]
Carrying Amount, Assets	0.5	11.3
Carrying Amount, Liabilities	0.0	0.0
Maximum exposure to loss	0.5	11.3
VIE Assets	45.5	432.3
Private equity vehicles [Member]
Variable Interest Entity [Line Items]
Carrying Amount, Assets	27.3	44.3
Carrying Amount, Liabilities	0.0	0.0
Maximum exposure to loss	40.7	59.2
VIE Assets	$ 80.8	$ 92.8