Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Debt securities, amortized cost	$ 141,951	$ 129,313
Equity securities, amortized cost	$ 13,167	$ 6,554
Common stock, no par value (in dollars per share)
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	9,598,155	9,592,861
Common stock, shares outstanding (in shares)	9,598,155	9,592,861