CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - UNAUDITED - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income/ (Loss)
Balance at beginning of period at Dec. 31, 2021	$ 1,519,679	$ 45,119	$ 751,072	$ 732,027	$ (8,539)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	43,935			43,935
Other comprehensive income (loss), net of tax	(60,732)				(60,732)
Comprehensive income/ (loss)	(16,797)
Common stock dividends	(15,615)			(15,615)
Stock compensation expense	1,472		1,472
Stock option plan	195	9	186
Employee stock purchase plan	436	10	426
Restricted stock vesting, net of tax withholding	(460)	25	(485)
Balance at end of period at Mar. 31, 2022	1,488,910	45,163	752,671	760,347	(69,271)
Balance at beginning of period at Dec. 31, 2022	1,483,768	44,657	734,273	836,789	(131,951)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	51,253			51,253
Other comprehensive income (loss), net of tax	15,960				15,960
Comprehensive income/ (loss)	67,213
Common stock dividends	(15,407)			(15,407)
Stock compensation expense	1,241		1,241
Stock option plan	151	7	144
Employee stock purchase plan	411	12	399
Restricted stock vesting, net of tax withholding	(512)	36	(548)
Balance at end of period at Mar. 31, 2023	$ 1,536,865	$ 44,712	$ 735,509	$ 872,635	$ (115,991)