Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Derivative Credit Risk Valuation Adjustment, Derivative Liabilities	$ 283	$ 19
Derivative liabilities	$ 62,000	$ 95,000
Weighted average discounted rate of estimated future premium payments to be paid by the VIEs	2.80%	2.20%
Derivative assets	$ 40,000	$ 76,000
Derivative assets	41,000	76,000
Warrants [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Derivative assets	1,000
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Other investments	$ 518,000	$ 577,000
Fixed Income Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Percentage of investment portfolio valued using dealer quotes	6.00%	6.00%
Minimum [Member] \| Fixed Income Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Percentage of investment portfolio valued using internal valuation models	4.00%	4.00%
Maximum [Member] \| Fixed Income Securities [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Percentage of investment portfolio valued using external pricing services	90.00%	90.00%
Variable Interest Entity, Primary Beneficiary [Member]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Derivative liabilities	$ 1,476,000	$ 1,940,000
Weighted average discounted rate of estimated future premium payments to be paid by the VIEs	5.00%	3.00%
Derivative assets	$ 51,000	$ 38,000
Derivative assets	$ 51,000	$ 38,000

Weighted average discounted rate of estimated future premium payments to be paid by the VIEs.

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Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]

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Investment portfolio valued using dealer quotes.

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Percentage of investment portfolio valued using external pricing services.

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Percentage of investment portfolio valued using internal valuation models.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Amount of investments classified as other.

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