Condensed Financial Information (Parent Company Only) Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Other investments	$ 690	$ 556
Other assets	19,055	16,892
Total assets	872,912	805,337
LIABILITIES
Other liabilities	9,878	6,255
Total liabilities	801,069	740,846
STOCKHOLDERS' EQUITY
Common stock, $2.00 par value; 7,500,000 shares authorized; 4,948,245 shares issued at December 31, 2019 and 4,943,690 shares issued at December 31, 2018	9,897	9,888
Additional-paid-in capital	1,124	894
Retained earnings	64,019	58,911
Treasury stock at cost; 476,268 shares at December 31, 2019 and 477,011 shares at December 31, 2018	(4,183)	(4,179)
Accumulated other comprehensive income (loss)	986	(1,023)
Total stockholders' equity	71,843	64,491	$ 58,661
Total liabilities and stockholders' equity	872,912	805,337
Parent Company [Member]
ASSETS
Cash	46	48	$ 77
Other investments	27	67
Investment in subsidiary - Union	71,500	64,180
Other assets	712	767
Total assets	72,285	65,062
LIABILITIES
Other liabilities	442	571
Total liabilities	442	571
STOCKHOLDERS' EQUITY
Common stock, $2.00 par value; 7,500,000 shares authorized; 4,948,245 shares issued at December 31, 2019 and 4,943,690 shares issued at December 31, 2018	9,897	9,888
Additional-paid-in capital	1,124	894
Retained earnings	64,019	58,911
Treasury stock at cost; 476,268 shares at December 31, 2019 and 477,011 shares at December 31, 2018	(4,183)	(4,179)
Accumulated other comprehensive income (loss)	986	(1,023)
Total stockholders' equity	71,843	64,491
Total liabilities and stockholders' equity	$ 72,285	$ 65,062