Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Retained Earnings		Treasury Stock	Accumulated Other Comprehensive Income
Balance at beginning of period at Dec. 31, 2019	$ 725,263	$ 560,263	$ 162,752	[1]	$ 0	$ 2,248
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	38,670		38,670	[1]
Other comprehensive income, net of tax	8,630					8,630
Purchase of treasury stock, 131,035 shares	(1,452)				(1,452)
Issuance of stock	2,046	2,046
Retirement of restricted stock	(492)	(492)
Cash dividends on common stock	(19,093)		(19,093)	[1]
Balance at end of period at Sep. 30, 2020	753,572	561,817	182,329	[1],[2]	(1,452)	10,878
Balance at beginning of period at Jun. 30, 2020	745,489	561,257	174,267	[2]	(1,452)	11,417
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	14,427		14,427	[2]
Other comprehensive income, net of tax	(539)					(539)
Issuance of stock	585	585
Retirement of restricted stock	(25)	(25)
Cash dividends on common stock	(6,365)		(6,365)	[2]
Balance at end of period at Sep. 30, 2020	753,572	561,817	182,329	[1],[2]	(1,452)	10,878
Balance at beginning of period at Dec. 31, 2020	763,784	562,421	191,418	[1]	(1,452)	11,397
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	72,871		72,871	[1]
Other comprehensive income, net of tax	(4,883)					(4,883)
Issuance of stock	3,154	3,154
Retirement of restricted stock	(620)	(620)
Exercise of stock options	19	19
Cash dividends on common stock	(20,197)		(20,197)	[1]
Balance at end of period at Sep. 30, 2021	814,128	564,974	244,092	[1],[2]	(1,452)	6,514
Balance at beginning of period at Jun. 30, 2021	796,676	563,980	228,803	[2]	(1,452)	5,345
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	22,289		22,289	[2]
Other comprehensive income, net of tax	1,169					1,169
Issuance of stock	958	958
Retirement of restricted stock	36	36
Cash dividends on common stock	(7,000)		(7,000)	[2]
Balance at end of period at Sep. 30, 2021	$ 814,128	$ 564,974	$ 244,092	[1],[2]	$ (1,452)	$ 6,514

[1] The Company adopted ASU 2016-13 at December 31, 2020, effective January 1, 2020, adjusting Retained Earnings by a negative $3,395. Retained earnings for the nine months ended September 30, 2020 have not been restated.

[2] The Company adopted ASU 2016-13 at December 31, 2020, effective January 1, 2020, adjusting Retained Earnings by a negative $3,395. Prior year periods have not been restated.