Variable Interest Entities - Additional Information (Detail) - USD ($) $ in Millions	May 31, 2019	Nov. 30, 2018
Related party private equity vehicles | JCP Entities
Variable Interest Entity [Line Items]
Equity investments	$ 139.3	$ 139.3
Funded equity commitments	121.5	121.3
Carrying amount of equity investment	31.2	35.5
Other investment vehicles
Variable Interest Entity [Line Items]
Equity investments	411.2	112.2
Funded equity commitments	397.7	108.1
Carrying amount of equity investment	396.4	95.0
Agency mortgage-backed securities
Variable Interest Entity [Line Items]
Carrying amount	1,525.1	2,913.0
Non-agency mortgage and other asset-backed securities
Variable Interest Entity [Line Items]
Carrying amount	$ 34.7	$ 170.5