CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2019	$ 750,115	$ 10,438	$ 379	$ 580,965	$ 159,033		$ (700)
Beginning balance, shares at Dec. 31, 2019		10,438	38,256,500
Net income	2,966				2,966
Other comprehensive income (loss), net of tax	11,048						11,048
Issuance of common stock upon exercise of stock options	677		$ 1	676
Issuance of common stock upon exercise of stock options, shares			55,402
Restricted stock activity, shares			174,036
Issuance of common stock in connection with employee stock purchase plan	268			268
Issuance of common stock in connection with employee stock purchase plan, shares			15,569
Cash dividends declared on preferred stock	(196)				(196)
Cash dividends declared on common stock	(1,151)				(1,151)
Repurchase of common stock	(1,668)					$ (1,668)
Repurchase of common stock, shares			(118,486)
Share-based compensation expense	608			608
Ending balance at Mar. 31, 2020	762,667	$ 10,438	$ 380	582,517	160,652	(1,668)	10,348
Ending balance, shares at Mar. 31, 2020		10,438	38,383,021
Beginning balance at Dec. 31, 2019	$ 750,115	$ 10,438	$ 379	580,965	159,033		(700)
Beginning balance, shares at Dec. 31, 2019		10,438	38,256,500
Repurchase of common stock, shares	(118,486)
Ending balance at Dec. 31, 2020	$ 805,464	$ 10,438	$ 384	587,165	191,098	(1,668)	18,047
Ending balance, shares at Dec. 31, 2020		10,438	38,618,054
Beginning balance at Mar. 31, 2020	762,667	$ 10,438	$ 380	582,517	160,652	(1,668)	10,348
Beginning balance, shares at Mar. 31, 2020		10,438	38,383,021
Net income	9,139				9,139
Other comprehensive income (loss), net of tax	9,685						9,685
Issuance of common stock upon exercise of stock options	56			56
Issuance of common stock upon exercise of stock options, shares			5,196
Restricted stock activity			$ 1	(1)
Cash dividends declared on preferred stock	(195)				(195)
Cash dividends declared on common stock	(1,152)				(1,152)
Share-based compensation expense	735			735
Ending balance at Jun. 30, 2020	780,935	$ 10,438	$ 381	583,307	168,444	(1,668)	20,033
Ending balance, shares at Jun. 30, 2020		10,438	38,388,217
Net income	13,071				13,071
Other comprehensive income (loss), net of tax	(709)						(709)
Issuance of common stock upon exercise of stock options	1,815		$ 1	1,814
Issuance of common stock upon exercise of stock options, shares			165,375
Restricted stock activity, shares			(5,886)
Issuance of common stock in connection with employee stock purchase plan	269		$ 1	268
Issuance of common stock in connection with employee stock purchase plan, shares			21,210
Cash dividends declared on preferred stock	(196)				(196)
Cash dividends declared on common stock	(1,157)				(1,157)
Share-based compensation expense	668			668
Ending balance at Sep. 30, 2020	794,696	$ 10,438	$ 383	586,057	180,162	(1,668)	19,324
Ending balance, shares at Sep. 30, 2020		10,438	38,568,916
Net income	12,291				12,291
Other comprehensive income (loss), net of tax	(1,277)						(1,277)
Issuance of common stock upon exercise of stock options	541		$ 1	540
Issuance of common stock upon exercise of stock options, shares			49,138
Cash dividends declared on preferred stock	(196)				(196)
Cash dividends declared on common stock	(1,159)				(1,159)
Share-based compensation expense	568			568
Ending balance at Dec. 31, 2020	805,464	$ 10,438	$ 384	587,165	191,098	(1,668)	18,047
Ending balance, shares at Dec. 31, 2020		10,438	38,618,054
Net income	21,798				21,798
Other comprehensive income (loss), net of tax	(26,394)						(26,394)
Issuance of common stock upon exercise of stock options	751		$ 1	750
Issuance of common stock upon exercise of stock options, shares			55,908
Restricted stock activity	(244)					(244)
Restricted stock activity, shares			274,739
Issuance of common stock in connection with employee stock purchase plan	515			515
Issuance of common stock in connection with employee stock purchase plan, shares			25,894
Cash dividends declared on preferred stock	(196)				(196)
Cash dividends declared on common stock	(2,315)				(2,315)
Repurchase of common stock	$ (6,363)					(6,363)
Repurchase of common stock, shares	(332,744)		(332,744)
Share-based compensation expense	$ 779			779
Ending balance at Mar. 31, 2021	$ 793,795	$ 10,438	$ 385	$ 589,209	$ 210,385	$ (8,275)	$ (8,347)
Ending balance, shares at Mar. 31, 2021		10,438	38,641,851