Investments - Debt and Short-term Investments (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Investment Holdings [Line Items]
Other investments	$ 52,406,000	$ 50,501,000
Investment in federal home loan bank stock	us-gaap:AssetPledgedAsCollateralMember	us-gaap:AssetPledgedAsCollateralMember
Cash and Short-term Investments
Investment in unconsolidated investees	$ 179,351,000	$ 171,311,000
Cash	72,148,000	88,804,000
Other Investments in Unconsolidated Investees
Cash and Short-term Investments
Investment in unconsolidated investees	10,900,000
Unfunded commitments	10,200,000
Maui Jim Inc.
Cash and Short-term Investments
Investment in unconsolidated investees	119,400,000
Prime Holdings Insurance Services, Inc. (Prime)
Cash and Short-term Investments
Investment in unconsolidated investees	49,000,000.0
FHLBC
Investment Holdings [Line Items]
Investments pledged as collateral	59,100,000
Federal home loan bank borrowings fair value disclosure	50,000,000.0
Investment In Low Income Housing Tax Credit Partnership Net Of Amortization
Investment Holdings [Line Items]
Other investments	15,800,000	16,600,000
Total tax benefit on investments in housing tax credit partnership	900,000	900,000
Qualified affordable housing project investments, commitment	1,400,000
Investment in Private Funds
Investment Holdings [Line Items]
Other investments	30,800,000	$ 28,600,000
Fair value investments entities that calculate net asset value per share unfunded commitments	$ 6,800,000