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, 2022	$ 1,483,768	$ 44,657	$ 734,273	$ 836,789	$ (131,951)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	96,744			96,744
Other comprehensive income, net of tax	(3,541)				(3,541)
Comprehensive income	93,203
Common stock dividends	(46,021)			(46,021)
Stock compensation expense	6,734		6,734
Stock option plan	705	58	647
Employee stock purchase plan	1,186	47	1,139
Restricted stock vesting, net of tax withholding	(1,661)	133	(1,794)
Balance at end of period at Sep. 30, 2023	1,537,914	44,895	740,999	887,512	(135,492)
Balance at beginning of period at Jun. 30, 2023	1,539,032	44,862	737,740	882,055	(125,625)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	20,746			20,746
Other comprehensive income, net of tax	(9,867)				(9,867)
Comprehensive income	10,879
Common stock dividends	(15,289)			(15,289)
Stock compensation expense	2,762		2,762
Stock option plan	188	17	171
Employee stock purchase plan	342	16	326
Balance at end of period at Sep. 30, 2023	1,537,914	44,895	740,999	887,512	(135,492)
Balance at beginning of period at Dec. 31, 2023	1,588,142	44,914	742,243	898,316	(97,331)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	59,388			59,388
Other comprehensive income, net of tax	21,430				21,430
Comprehensive income	80,818
Common stock dividends	(46,293)			(46,293)
Stock compensation expense	6,441		6,441
Stock option plan	117	11	106
Employee stock purchase plan	1,013	48	965
Restricted stock vesting, net of tax withholding	(1,401)	152	(1,553)
Balance at end of period at Sep. 30, 2024	1,628,837	45,125	748,202	911,411	(75,901)
Balance at beginning of period at Jun. 30, 2024	1,599,004	45,110	745,336	910,552	(101,994)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,209			16,209
Other comprehensive income, net of tax	26,093				26,093
Comprehensive income	42,302
Common stock dividends	(15,350)			(15,350)
Stock compensation expense	2,580		2,580
Stock option plan	8	1	7
Employee stock purchase plan	294	13	281
Restricted stock vesting, net of tax withholding	(1)	1	(2)
Balance at end of period at Sep. 30, 2024	$ 1,628,837	$ 45,125	$ 748,202	$ 911,411	$ (75,901)