Investment Information - Other investments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule Of Other Investments [Line Items]
Other investments, at fair value	$ 1,686,666	$ 1,973,550
Fixed maturities
Schedule Of Other Investments [Line Items]
Other investments, at fair value	426,187	416,698
Other investments
Schedule Of Other Investments [Line Items]
Other investments, at fair value	1,226,808	1,432,553
Other investments | Lending
Schedule Of Other Investments [Line Items]
Other investments, at fair value	472,099	536,345
Other investments | Investment grade fixed income
Schedule Of Other Investments [Line Items]
Other investments, at fair value	350,217	147,810
Other investments | Term loan investments
Schedule Of Other Investments [Line Items]
Other investments, at fair value	160,945	484,950
Other investments | Private equity
Schedule Of Other Investments [Line Items]
Other investments, at fair value	98,471	91,126
Other investments | Energy
Schedule Of Other Investments [Line Items]
Other investments, at fair value	81,693	81,692
Other investments | Credit related funds
Schedule Of Other Investments [Line Items]
Other investments, at fair value	63,383	70,278
Other investments | Infrastructure
Schedule Of Other Investments [Line Items]
Other investments, at fair value	0	20,352
Short-term investments
Schedule Of Other Investments [Line Items]
Other investments, at fair value	12,371	97,806
Equity securities
Schedule Of Other Investments [Line Items]
Other investments, at fair value	$ 21,300	$ 26,493