Investments - Additional Information (Details) $ in Millions	3 Months Ended
Mar. 31, 2023 USD ($) security	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Investments, Debt and Equity Securities [Abstract]
Gross unrealized losses	$ 17.9		$ 23.3
Realized investment losses (less than)	0.1	$ 0.1
Gross unrealized losses, twelve months or more	$ 15.9		$ 21.0
Number of debt securities held, unrealized loss position \| security	239
Financing receivable, allowance for credit loss	$ 0.0

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

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Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount of realized gain (loss) on investment.

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