Investments - Debt and Short-term Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Nov. 10, 2021
Investment Holdings [Line Items]
Other investments	$ 47,922	$ 50,501
Fixed maturities and short-term investments on deposit with either regulatory authorities or banks	88,600
FHLBC
Investment Holdings [Line Items]
Investments pledged as collateral	$ 57,300
Investment in federal home loan bank stock	us-gaap:AssetPledgedAsCollateralMember	us-gaap:AssetPledgedAsCollateralMember
Federal home loan bank borrowings fair value disclosure	$ 50,000			$ 50,000
Investment In Low Income Housing Tax Credit Partnership Net Of Amortization
Investment Holdings [Line Items]
Other investments	13,500	$ 16,600
Total tax benefit on investments in housing tax credit partnership	3,400	3,600	$ 3,500
Qualified affordable housing project investments, commitment	1,300
Investment in Private Funds
Investment Holdings [Line Items]
Other investments	28,400	$ 28,600
Fair value investments entities that calculate net asset value per share unfunded commitments	$ 4,900