Investment Information - Other investments (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule Of Other Investments [Line Items]
Other investments, at fair value	$ 1,634,368	$ 1,973,550
Fixed maturities
Schedule Of Other Investments [Line Items]
Other investments, at fair value	525,451	416,698
Other investments
Schedule Of Other Investments [Line Items]
Other investments, at fair value	1,054,771	1,432,553
Other investments | Lending
Schedule Of Other Investments [Line Items]
Other investments, at fair value	427,812	536,345
Other investments | Investment grade fixed income
Schedule Of Other Investments [Line Items]
Other investments, at fair value	221,484	147,810
Other investments | Term loan investments
Schedule Of Other Investments [Line Items]
Other investments, at fair value	152,277	484,950
Other investments | Private equity
Schedule Of Other Investments [Line Items]
Other investments, at fair value	124,282	91,126
Other investments | Energy
Schedule Of Other Investments [Line Items]
Other investments, at fair value	74,234	81,692
Other investments | Credit related funds
Schedule Of Other Investments [Line Items]
Other investments, at fair value	54,682	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	39,657	97,806
Equity securities
Schedule Of Other Investments [Line Items]
Other investments, at fair value	$ 14,489	$ 26,493