Commitments and Contingencies (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Loss Contingencies [Line Items]
Net gain from sale of discontinued operations, net of tax	$ 18.7	$ 0.9
Sirius Group \| Discontinued Operations
Loss Contingencies [Line Items]
Net gain from sale of discontinued operations, net of tax	$ 17.6

Amount after tax of gain (loss) not previously recognized resulting from the disposal of a discontinued operation.

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