Acquisition of Business - Narrative (Details) - American Access Casualty Company		3 Months Ended
Nov. 23, 2020 USD ($)	Sep. 30, 2021 agent	Mar. 31, 2021 USD ($)
Business Acquisition [Line Items]
Cash consideration	$ 370,900,000
Direct premiums			$ 350,000,000
Number of independent agents \| agent		600

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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