Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt securities, available-for-sale, Amortized cost (in dollars)	$ 569,498	$ 550,268
Equity securities, available for sale, cost (in dollars)	71,895	68,709
Other investments, cost	$ 3,763	$ 3,763
Common stock, par value (in dollars per share)	$ 0.18	$ 0.18
Common stock, authorized shares	33,333,333	33,333,333
Common stock, issued shares	20,872,831	20,872,831
Treasury stock, shares	2,749,738	2,846,131
Senior unsecured notes due 2029 [Member]
Unamortized debt issuance cost (in dollars)	$ 942
Subordinated Debt [Member]
Unamortized debt issuance cost (in dollars)	$ 846	$ 898