Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Cumulative Effect, Period of Adoption, Adjustment [Member] Common Stock Outstanding [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] AOCI Attributable to Parent [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Treasury Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock Outstanding [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance (in shares) at Dec. 31, 2020							79,508,265
Beginning balance, loss, net of tax (Accounting Standards Update 2016-13 [Member]) at Dec. 31, 2020	$ 0	$ 0	$ 0	$ (3,139)	$ 0	$ (3,139)
Beginning balance, loss, net of tax at Dec. 31, 2020							$ 906	$ 964,734	$ 5,310	$ 1,789,325	$ (342,131)	$ 2,418,144
Dividend Reinvestment Plan (in shares)							62,326
Dividend Reinvestment Plan							$ 1	2,618	0	0	0	2,619
Restricted stock units vested (in shares)							123,893
Restricted stock units vested							$ 1	0	0	0	0	1
Shares withheld related to net share settlement of RSUs							$ 0	(2,632)	0	0	0	(2,632)
Purchases of treasury stock (in shares)							(2,475,019)
Purchases of treasury stock							$ 0	0	0	0	(100,668)	(100,668)
Stock-based compensation							0	4,149	0	0	0	4,149
Cash dividends							0	0	0	(73,335)	0	(73,335)
Other comprehensive income (loss)							0	0	(5,678)	0	0	(5,678)
Net income							0	0	0	222,980	0	222,980
Stock issued to directors							$ 0	850	0	0	0	850
Balance (in shares) at Sep. 30, 2021							77,240,215
Ending balance, loss, net of tax at Sep. 30, 2021							$ 908	969,719	(368)	1,935,831	(442,799)	2,463,291
Balance (in shares) at Jun. 30, 2021							78,158,590
Beginning balance, loss, net of tax at Jun. 30, 2021							$ 908	967,166	2,372	1,887,571	(405,660)	2,452,357
Dividend Reinvestment Plan (in shares)							22,267
Dividend Reinvestment Plan							$ 0	894	0	0	0	894
Restricted stock units vested (in shares)							1,971
Restricted stock units vested							$ 0	0	0	0	0	0
Shares withheld related to net share settlement of RSUs							$ 0	(38)	0	0	0	(38)
Purchases of treasury stock (in shares)							(942,613)
Purchases of treasury stock							$ 0	0	0	0	(37,139)	(37,139)
Stock-based compensation							0	1,697	0	0	0	1,697
Cash dividends							0	0	0	(24,137)	0	(24,137)
Other comprehensive income (loss)							0	0	(2,740)	0	0	(2,740)
Net income							$ 0	0	0	72,397	0	72,397
Balance (in shares) at Sep. 30, 2021							77,240,215
Ending balance, loss, net of tax at Sep. 30, 2021							$ 908	969,719	(368)	1,935,831	(442,799)	2,463,291
Balance (in shares) at Dec. 31, 2021							75,750,862
Beginning balance, loss, net of tax at Dec. 31, 2021							$ 909	972,474	(3,065)	1,985,168	(509,235)	2,446,251
Dividend Reinvestment Plan (in shares)							65,142
Dividend Reinvestment Plan							$ 1	2,791	0	0	0	2,792
Restricted stock units vested (in shares)							110,641
Restricted stock units vested							$ 1	0	0	0	0	1
Shares withheld related to net share settlement of RSUs							$ 0	(2,864)	0	0	0	(2,864)
Purchases of treasury stock (in shares)							(2,534,465)
Purchases of treasury stock							$ 0	0	0	0	(109,774)	(109,774)
Stock-based compensation							0	5,183	0	0	0	5,183
Cash dividends							0	0	0	(76,111)	0	(76,111)
Other comprehensive income (loss)							0	0	(109,809)	0	0	(109,809)
Net income							$ 0	0	0	263,041	0	263,041
Stock issued to directors (in shares)							19,780
Stock issued to directors							$ 0	849	0	0	0	849
Balance (in shares) at Sep. 30, 2022							73,411,960
Ending balance, loss, net of tax at Sep. 30, 2022							$ 911	978,433	(112,874)	2,172,098	(619,009)	2,419,559
Balance (in shares) at Jun. 30, 2022							74,421,884
Beginning balance, loss, net of tax at Jun. 30, 2022							$ 910	976,547	(71,328)	2,098,122	(572,719)	2,431,532
Dividend Reinvestment Plan (in shares)							21,880
Dividend Reinvestment Plan							$ 1	919	0	0	0	920
Restricted stock units vested (in shares)							47,736
Restricted stock units vested							$ 0	0	0	0	0	0
Shares withheld related to net share settlement of RSUs							$ 0	(849)	0	0	0	$ (849)
Purchases of treasury stock (in shares)							(1,079,540)					(1,080,000.00)
Purchases of treasury stock							$ 0	0	0	0	(46,290)	$ (46,290)
Stock-based compensation							0	1,816	0	0	0	1,816
Cash dividends							0	0	0	(25,059)	0	(25,059)
Other comprehensive income (loss)							0	0	(41,546)	0	0	(41,546)
Net income							$ 0	0	0	99,035	0	99,035
Balance (in shares) at Sep. 30, 2022							73,411,960
Ending balance, loss, net of tax at Sep. 30, 2022							$ 911	$ 978,433	$ (112,874)	$ 2,172,098	$ (619,009)	$ 2,419,559