Investments - Schedule of Investment Funds (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Alternative Investment [Line Items]
Investment funds, Unfunded Commitments	$ 725,000
Commercial mortgage loans
Alternative Investment [Line Items]
Investment funds, Fair Value	404,782	$ 431,405
Investment funds, Unfunded Commitments	583,694
Opportunistic credit
Alternative Investment [Line Items]
Investment funds, Fair Value	161,054	158,524
Investment funds, Unfunded Commitments	$ 0
Investments, initial redemption, term	2 years
Investments, redemption, term	36 months
Infrastructure
Alternative Investment [Line Items]
Investment funds, Fair Value	$ 161,071	159,534
Investment funds, Unfunded Commitments	21,648
Other investments
Alternative Investment [Line Items]
Investment funds, Fair Value	32,250	19,226
Investment funds, Unfunded Commitments	120,048
Investment funds
Alternative Investment [Line Items]
Investment funds, Fair Value	759,157	$ 768,689
Investment funds, Unfunded Commitments	$ 725,390