CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Preferred stock	Common stock	Capital surplus	Retained earnings	Accumulated other comprehensive (loss)	Total
Beginning Balance at Dec. 31, 2018	$ 2,781	$ 238	$ 473,833	$ 133,781	$ (2,108)	$ 608,525
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				13,982		13,982
Other comprehensive income					5,588	5,588
Common dividends declared				(5,823)		(5,823)
Preferred dividends declared				(82)		(82)
Preferred stock, premium amortization	(48)			48		48
Share-based compensation expense			846			846
Issuance of common stock under employee benefit plans			1,132			1,132
Ending Balance at Mar. 31, 2019	$ 2,733	238	475,811	141,906	3,480	624,168
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principles				(7,172)		(7,172)
Adjusted balances		244	488,305	158,748	7,442	654,739
Beginning Balance at Dec. 31, 2019		244	488,305	165,920	7,442	661,911
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				1,549		1,549
Other comprehensive income					1,012	1,012
Common dividends declared				(6,575)		(6,575)
Common stock repurchased		(10)	(20,552)			(20,562)
Share-based compensation expense			602			602
Issuance of common stock under employee benefit plans			395			395
Ending Balance at Mar. 31, 2020		$ 234	$ 468,750	$ 153,722	$ 8,454	$ 631,160