Consolidated Statements of Changes in Stockholders' Equity - 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, Common [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, Common [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	[1]	$ 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)								84,011					84,011
Dividend Reinvestment Plan								$ 1	3,562	0	0	0	$ 3,563
Restricted stock units vested (in shares)								123,893
Restricted stock units vested								$ 2	0	0	0	0	2
Shares withheld related to net share settlement of RSUs								$ 0	(2,632)	0	0	0	(2,632)
Stock issued to directors (in shares)								20,750
Stock issued to directors								$ 0	850	0	0	0	850
Purchases of treasury stock (in shares)								(3,986,057)
Purchases of treasury stock								$ 0	0	0	0	(167,104)	(167,104)
Stock -based compensation								0	5,960	0	0	0	5,960
Cash dividends								0	0	0	(99,322)	0	(99,322)
Other comprehensive income/(loss)								0	0	(8,375)	0	0	(8,375)
Net income								$ 0	0	0	298,304	0	298,304
Balance (in shares) at Dec. 31, 2021								75,750,862
Ending 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)								86,501					86,501
Dividend Reinvestment Plan								$ 1	3,718	0	0	0	$ 3,719
Restricted stock units vested (in shares)								112,473
Restricted stock units vested								$ 1	0	0	0	0	1
Shares withheld related to net share settlement of RSUs								$ 0	(2,905)	0	0	0	(2,905)
Stock issued to directors (in shares)								19,780
Stock issued to directors								$ 0	849	0	0	0	$ 849
Purchases of treasury stock (in shares)								(3,227,465)					(3,227,465)
Purchases of treasury stock								$ 0	0	0	0	(141,315)	$ (141,315)
Stock -based compensation								0	6,983	0	0	0	6,983
Cash dividends								0	0	0	(100,955)	0	(100,955)
Other comprehensive income/(loss)								0	0	(99,230)	0	0	(99,230)
Net income								$ 0	0	0	360,642	0	360,642
Balance (in shares) at Dec. 31, 2022								72,742,151
Ending balance, loss, net of tax at Dec. 31, 2022								$ 911	981,119	(102,295)	2,244,855	(650,550)	$ 2,474,040
Dividend Reinvestment Plan (in shares)								93,182					93,182
Dividend Reinvestment Plan								$ 1	3,490	0	0	0	$ 3,491
Restricted stock units vested (in shares)								183,324
Restricted stock units vested								$ 2	0	0	0	0	2
Shares withheld related to net share settlement of RSUs								$ 0	(4,490)	0	0	0	(4,490)
Stock issued to directors (in shares)								25,360
Stock issued to directors								$ 0	850	0	0	0	850
Purchases of treasury stock (in shares)								(375,090)
Purchases of treasury stock								$ 0	0	0	0	(16,667)	(16,667)
Stock -based compensation								0	6,984	0	0	0	6,984
Cash dividends								0	0	0	(98,638)	0	(98,638)
Other comprehensive income/(loss)								0	0	16,879	0	0	16,879
Net income								$ 0	0	0	354,124	0	354,124
Balance (in shares) at Dec. 31, 2023								72,668,927
Ending balance, loss, net of tax at Dec. 31, 2023								$ 914	$ 987,953	$ (85,416)	$ 2,500,341	$ (667,217)	$ 2,736,575

[1] Represents the impact of the adoption of Accounting Standards Update ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) on January 1, 2021.