Investments - Schedule of Other Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Investments [Line Items]
Other investments	$ 2,494,954	$ 1,993,059
Initial commitments	2,900,000	2,700,000
Fulfilled commitments	1,700,000	1,300,000
Unfunded commitments	1,200,000	1,400,000
Other investments
Schedule of Investments [Line Items]
Net unrealized gain (loss) recognized in earnings due to change in estimate	19,800	7,000	$ (2,400)
Catastrophe bonds
Schedule of Investments [Line Items]
Other investments	$ 1,241,468	1,104,034
Catastrophe bonds | Low
Schedule of Investments [Line Items]
Maturity period	1 year
Catastrophe bonds | High
Schedule of Investments [Line Items]
Maturity period	5 years
Fund investments
Schedule of Investments [Line Items]
Other investments	$ 1,086,706	725,802
Direct private equity investments
Schedule of Investments [Line Items]
Other investments	66,780	88,373
Term loans
Schedule of Investments [Line Items]
Other investments	$ 100,000	$ 74,850