Consolidated Statements of Changes in Shareholders' Equity (unaudited) - USD ($) $ in Thousands	Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Dec. 31, 2021	$ 173,331	$ 3,653,098	$ 997,657	$ (21,146)	$ 4,802,940
Balance (in shares) at Dec. 31, 2021	69,332,297
Increase (Decrease) in Stockholders' Equity
Net Income (Loss)			352,547		352,547
Other comprehensive income (loss), net of tax effects				(695,312)	(695,312)
Total comprehensive income (loss)					(342,765)
Cash dividends declared on common stock per share			(108,639)		(108,639)
Cash dividends equivalents paid on restricted stock units			(152)		(152)
Employee stock purchases	$ 48	1,395			1,443
Employee stock purchases (in shares)	19,162
Stock options exercised	$ 92	1,424			1,516
Stock options exercised (in shares)	37,236
Restricted stock awards (forfeits)	$ (6)	6
Restricted stock awards (forfeits) (in shares)	(2,816)
Stock issued pursuant to restricted stock units	$ 958	(957)			1
Stock issued pursuant to restricted stock units (in shares)	383,369
Common stock repurchased - buyback plan	$ (3,280)	(106,924)			(110,204)
Common stock repurchased - buyback plan (in shares)	(1,312,038)
Common stock repurchased	$ (279)	(8,778)			(9,057)
Common stock repurchased (in shares)	(111,568)
Share-based compensation expense		28,311			28,311
Common stock issued for acquisition	$ 18,327	641,445			659,772
Common stock issued for acquisition (in shares)	7,330,803
Net fair value of unvested equity awards assumed in the Atlantic Capital acquisition		(1,980)			(1,980)
Balance at Sep. 30, 2022	$ 189,191	4,207,040	1,241,413	(716,458)	4,921,186
Balance (in shares) at Sep. 30, 2022	75,676,445
Balance at Dec. 31, 2021	$ 173,331	3,653,098	997,657	(21,146)	4,802,940
Balance (in shares) at Dec. 31, 2021	69,332,297
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				75,704,563
Balance at Jun. 30, 2022	$ 189,103	4,195,976	1,146,230	(490,884)	$ 5,040,425
Balance (in shares) at Jun. 30, 2022	75,641,322
Increase (Decrease) in Stockholders' Equity
Net Income (Loss)			133,043		133,043
Other comprehensive income (loss), net of tax effects				(225,574)	(225,574)
Total comprehensive income (loss)					(92,531)
Cash dividends declared on common stock per share			(37,834)		(37,834)
Cash dividends equivalents paid on restricted stock units			(26)		(26)
Employee stock purchases	$ 25	714			739
Employee stock purchases (in shares)	10,084
Stock options exercised	$ 47	732			779
Stock options exercised (in shares)	18,980
Restricted stock awards (forfeits)	$ (3)	3
Restricted stock awards (forfeits) (in shares)	(1,550)
Stock issued pursuant to restricted stock units	$ 46	(46)
Stock issued pursuant to restricted stock units (in shares)	18,560
Common stock repurchased	$ (27)	(851)			(878)
Common stock repurchased (in shares)	(10,951)
Share-based compensation expense		10,512			10,512
Balance at Sep. 30, 2022	$ 189,191	4,207,040	1,241,413	(716,458)	4,921,186
Balance (in shares) at Sep. 30, 2022	75,676,445
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				75,704,563
Increase (Decrease) in Stockholders' Equity
Net Income (Loss)			387,517		$ 387,517
Other comprehensive income (loss), net of tax effects				(138,801)	(138,801)
Total comprehensive income (loss)					248,716
Cash dividends declared on common stock per share			(115,400)		(115,400)
Cash dividends equivalents paid on restricted stock units			(1,079)		(1,079)
Employee stock purchases	$ 52	1,304			1,356
Employee stock purchases (in shares)	20,903
Stock options exercised	$ 68	1,324			1,392
Stock options exercised (in shares)	27,156
Restricted stock awards (forfeits)	$ (7)	7
Restricted stock awards (forfeits) (in shares)	(2,559)
Stock issued pursuant to restricted stock units	$ 927	(927)
Stock issued pursuant to restricted stock units (in shares)	370,493
Common stock repurchased	$ (258)	(7,151)			(7,409)
Common stock repurchased (in shares)	(103,190)
Share-based compensation expense		28,484			28,484
Balance at Sep. 30, 2023	$ 190,043	4,238,753	1,618,080	(815,889)	$ 5,230,987
Balance (in shares) at Sep. 30, 2023	76,017,366				76,017,366
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
Increase (Decrease) in Stockholders' Equity
Net Income (Loss)			124,144		124,144
Other comprehensive income (loss), net of tax effects				(153,491)	(153,491)
Total comprehensive income (loss)					(29,347)
Cash dividends declared on common stock per share			(39,526)		(39,526)
Cash dividends equivalents paid on restricted stock units			(46)		(46)
Employee stock purchases	$ 28	681			709
Employee stock purchases (in shares)	11,341
Stock options exercised	$ 9	210			219
Stock options exercised (in shares)	3,640
Restricted stock awards (forfeits)	$ (1)	1
Restricted stock awards (forfeits) (in shares)	(206)
Stock issued pursuant to restricted stock units	$ 30	(30)
Stock issued pursuant to restricted stock units (in shares)	11,709
Common stock repurchased	$ (13)	(374)			(387)
Common stock repurchased (in shares)	(5,097)
Share-based compensation expense		9,355			9,355
Balance at Sep. 30, 2023	$ 190,043	$ 4,238,753	$ 1,618,080	$ (815,889)	$ 5,230,987
Balance (in shares) at Sep. 30, 2023	76,017,366				76,017,366