Variable Interest Entities - Non-consolidated VIEs - Additional Information (Details) - USD ($) $ in Millions	Nov. 30, 2019	Nov. 30, 2018
Variable Interest Entity [Line Items]
Nonconsolidated VIEs, assets carrying amount	$ 938.0	$ 634.7
Related party private equity vehicles
Variable Interest Entity [Line Items]
Nonconsolidated VIEs, assets carrying amount	23.0	35.5
Related party private equity vehicles | JCP Entities
Variable Interest Entity [Line Items]
Equity commitments amount	133.0	139.3
Funded equity commitments	121.7	121.3
Carrying amount of equity investment	23.0	35.5
Other investment vehicles
Variable Interest Entity [Line Items]
Equity commitments amount	398.6	112.2
Funded equity commitments	390.8	108.1
Carrying amount of equity investment	404.1	95.0
Nonconsolidated VIEs, assets carrying amount	404.1	95.0
Agency mortgage-backed securities
Variable Interest Entity [Line Items]
Nonconsolidated VIEs, assets carrying amount	1,453.5	2,913.0
Non-agency mortgage and other asset-backed securities
Variable Interest Entity [Line Items]
Nonconsolidated VIEs, assets carrying amount	$ 134.8	$ 170.5