Derivative Financial Instruments - External Credit Ratings of Underlyings or Referenced Assets (Details) - USD ($) $ in Millions	Feb. 28, 2023	Nov. 30, 2022
Index credit default swaps
Derivative [Line Items]
Derivative notional amount	$ 1,142.0	$ 723.7
Single name credit default swaps
Derivative [Line Items]
Derivative notional amount	0.2	0.2
Investment Grade | Index credit default swaps
Derivative [Line Items]
Derivative notional amount	241.5	207.9
Investment Grade | Single name credit default swaps
Derivative [Line Items]
Derivative notional amount	0.0	0.0
Non-investment Grade | Index credit default swaps
Derivative [Line Items]
Derivative notional amount	900.5	515.8
Non-investment Grade | Single name credit default swaps
Derivative [Line Items]
Derivative notional amount	0.0	0.0
Unrated | Index credit default swaps
Derivative [Line Items]
Derivative notional amount	0.0	0.0
Unrated | Single name credit default swaps
Derivative [Line Items]
Derivative notional amount	$ 0.2	$ 0.2