Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Available-for-sale, amortized cost	$ 1,656,797	$ 1,720,291
Available-for-sale securities, allowance for credit losses	0	5
Equity securities, cost	84,605	49,085
Allowance for doubtful accounts	781	687
Property and equipment, accumulated depreciation	60,142	55,141
Reinsurance receivables, allowance for credit losses	$ 102	$ 190
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	25,082,104	25,055,479
Common stock, shares outstanding (in shares)	25,082,104	25,055,479