Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Forfeiture of restricted stock award grants (in shares)	2,699	361	2,482
Restricted stock award grants (in shares)	40,978	40,108	39,673
Performance based restricted stock award grants (in shares)	798
Issuance of common stock, net of issuance costs (in shares)	52,568		834,896
Purchase of treasury stock (in shares)	40,000	90,898	70,202
Cash dividends declared (in dollars per share)	$ 0.68	$ 0.67	$ 0.66
Restricted Stock
Purchase of treasury stock (in shares)	10,647	6,308	4,960
Performance Shares
Purchase of treasury stock (in shares)	294