Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Recent Acquisitions, Disposals & Other Transactions - Acquisitions (Details) - USD ($) $ in Millions	Jun. 12, 2020	Oct. 12, 2020
ArgoGlobal \| RiverStone \| ArgoGlobal Syndicate 1200
Business Acquisition [Line Items]
Reinsurance-to-close transaction, net technical provision		$ 219.7
Ariel Indemnity Limited
Business Acquisition [Line Items]
Percentage of capital stock acquired	100.00%
Consideration transferred	$ 55.6