Investments - Debt and Short-term Investments (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Investment Holdings [Line Items]
Other investments	$ 51,018,000		$ 51,018,000		$ 50,501,000
Investment in federal home loan bank stock	us-gaap:AssetPledgedAsCollateralMember		us-gaap:AssetPledgedAsCollateralMember		us-gaap:AssetPledgedAsCollateralMember
Cash and Short-term Investments
Investment in unconsolidated investees	$ 187,310,000		$ 187,310,000		$ 171,311,000
Cash	113,044,000		113,044,000		88,804,000
Other Investments in Unconsolidated Investees
Cash and Short-term Investments
Investment in unconsolidated investees	12,300,000		12,300,000
Unfunded commitments	8,600,000		8,600,000
Maui Jim Inc.
Cash and Short-term Investments
Investment in unconsolidated investees	127,400,000		127,400,000
Prime Holdings Insurance Services, Inc. (Prime)
Cash and Short-term Investments
Investment in unconsolidated investees	47,600,000		47,600,000
FHLBC
Investment Holdings [Line Items]
Investments pledged as collateral	58,200,000		58,200,000
Federal home loan bank borrowings fair value disclosure	50,000,000.0		50,000,000.0
Investment In Low Income Housing Tax Credit Partnership Net Of Amortization
Investment Holdings [Line Items]
Other investments	15,100,000		15,100,000		16,600,000
Total tax benefit on investments in housing tax credit partnership	900,000	$ 900,000	1,700,000	$ 1,800,000
Qualified affordable housing project investments, commitment	1,300,000		1,300,000
Investment in Private Funds
Investment Holdings [Line Items]
Other investments	30,300,000		30,300,000		$ 28,600,000
Fair value investments entities that calculate net asset value per share unfunded commitments	$ 5,900,000		$ 5,900,000