Consolidated Statements of Changes in Shareholders' Equity (unaudited) - USD ($) $ in Thousands	Common Stock	Surplus	Retained Earnings Cumulative Effect of Adoption of ASU	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Cumulative Effect of Adoption of ASU	Total
Balance at Dec. 31, 2022	$ 189,261	$ 4,215,712		$ 1,347,042	$ (677,088)		$ 5,074,927
Balance (in shares) at Dec. 31, 2022	75,704,563
Increase (Decrease) in Stockholders' Equity
Net Income (Loss)				263,373			263,373
Other comprehensive income (loss), net of tax effects					14,690		14,690
Total comprehensive income (loss)							278,063
Cash dividends declared on common stock per share				(75,874)			(75,874)
Cash dividend equivalents paid on restricted stock units				(1,033)			(1,033)
Employee stock purchases	$ 24	623					647
Employee stock purchases (in shares)	9,562
Stock options exercised	$ 59	1,114					1,173
Stock options exercised (in shares)	23,516
Restricted stock awards (forfeits)	$ (6)	6
Restricted stock awards (forfeits) (in shares)	(2,353)
Stock issued pursuant to restricted stock units	$ 897	(897)
Stock issued pursuant to restricted stock units (in shares)	358,784
Common stock repurchased	$ (245)	(6,777)					(7,022)
Common stock repurchased (in shares)	(98,093)
Share-based compensation expense		19,129					19,129
Balance at Jun. 30, 2023	$ 189,990	4,228,910		1,533,508	(662,398)		5,290,010
Balance (in shares) at Jun. 30, 2023	75,995,979
Balance at Dec. 31, 2022	$ 189,261	4,215,712		1,347,042	(677,088)		5,074,927
Balance (in shares) at Dec. 31, 2022	75,704,563
Balance at Dec. 31, 2023	$ 190,055	4,240,413		1,685,166	(582,536)		$ 5,533,098
Balance (in shares) at Dec. 31, 2023	76,022,039						76,022,039
Balance at Mar. 31, 2023	$ 189,649	4,224,503		1,448,636	(613,784)		$ 5,249,004
Balance (in shares) at Mar. 31, 2023	75,859,665
Increase (Decrease) in Stockholders' Equity
Net Income (Loss)				123,447			123,447
Other comprehensive income (loss), net of tax effects					(48,614)		(48,614)
Total comprehensive income (loss)							74,833
Cash dividends declared on common stock per share				(37,962)			(37,962)
Cash dividend equivalents paid on restricted stock units				(613)			(613)
Employee stock purchases	$ 24	623					647
Employee stock purchases (in shares)	9,562
Restricted stock awards (forfeits)	$ (1)	1
Restricted stock awards (forfeits) (in shares)	(120)
Stock issued pursuant to restricted stock units	$ 453	(453)
Stock issued pursuant to restricted stock units (in shares)	181,076
Common stock repurchased	$ (135)	(3,471)					(3,606)
Common stock repurchased (in shares)	(54,204)
Share-based compensation expense		7,707					7,707
Balance at Jun. 30, 2023	$ 189,990	4,228,910		1,533,508	(662,398)		5,290,010
Balance (in shares) at Jun. 30, 2023	75,995,979
Balance at Dec. 31, 2023	$ 190,055	4,240,413		1,685,166	(582,536)		$ 5,533,098
Balance (in shares) at Dec. 31, 2023	76,022,039						76,022,039
Increase (Decrease) in Stockholders' Equity
Net Income (Loss)				247,426			$ 247,426
Other comprehensive income (loss), net of tax effects					(37,675)		(37,675)
Total comprehensive income (loss)							209,751
Cash dividends declared on common stock per share				(79,217)			(79,217)
Cash dividend equivalents paid on restricted stock units				(1,196)			(1,196)
Employee stock purchases	$ 23	707					730
Employee stock purchases (in shares)	9,092
Stock options exercised	$ 19	422					441
Stock options exercised (in shares)	7,448
Restricted stock awards (forfeits)	$ (2)	2
Restricted stock awards (forfeits) (in shares)	(316)
Stock issued pursuant to restricted stock units	$ 884	(884)
Stock issued pursuant to restricted stock units (in shares)	353,675
Stock issued in lieu of cash - directors fees	$ 3	90					93
Stock issued in lieu of cash - directors fees (in shares)	1,148
Common stock repurchased - buyback plan	$ (250)	(7,735)					(7,985)
Common stock repurchased - buyback plan (in shares)	(100,000)
Common stock repurchased	$ (243)	(7,850)					(8,093)
Common stock repurchased (in shares)	(97,363)
Share-based compensation expense		13,027					13,027
Balance (ASU 2023-02) at Jun. 30, 2024			$ (10,246)			$ (10,246)
Balance at Jun. 30, 2024	$ 190,489	4,238,192		1,841,933	(620,211)		$ 5,650,403
Balance (in shares) at Jun. 30, 2024	76,195,723						76,195,723
Balance at Mar. 31, 2024	$ 190,443	4,230,345		1,749,215	(622,994)		$ 5,547,009
Balance (in shares) at Mar. 31, 2024	76,177,163
Increase (Decrease) in Stockholders' Equity
Net Income (Loss)				132,370			132,370
Other comprehensive income (loss), net of tax effects					2,783		2,783
Total comprehensive income (loss)							135,153
Cash dividends declared on common stock per share				(39,619)			(39,619)
Cash dividend equivalents paid on restricted stock units				(33)			(33)
Employee stock purchases	$ 23	707					730
Employee stock purchases (in shares)	9,092
Stock options exercised	$ 3	47					50
Stock options exercised (in shares)	1,099
Restricted stock awards (forfeits)	$ (1)	1
Restricted stock awards (forfeits) (in shares)	(252)
Stock issued pursuant to restricted stock units	$ 23	(23)
Stock issued pursuant to restricted stock units (in shares)	9,299
Stock issued in lieu of cash - directors fees	$ 3	90					93
Stock issued in lieu of cash - directors fees (in shares)	1,148
Common stock repurchased	$ (5)	(135)					(140)
Common stock repurchased (in shares)	(1,826)
Share-based compensation expense		7,160					7,160
Balance (ASU 2023-02) at Jun. 30, 2024			$ (10,246)			$ (10,246)
Balance at Jun. 30, 2024	$ 190,489	$ 4,238,192		$ 1,841,933	$ (620,211)		$ 5,650,403
Balance (in shares) at Jun. 30, 2024	76,195,723						76,195,723