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	$ (3,140)	$ 0	$ (3,140)
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)							20,036
Dividend Reinvestment Plan							$ 0	868	0	0	0	868
Restricted stock units vested (in shares)							66,724
Restricted stock units vested							$ 1	0	0	0	0	1
Shares withheld related to net share settlement of RSUs							0	(1,279)	0	0	0	(1,279)
Stock-based compensation							0	1,243	0	0	0	1,243
Cash dividends							0	0	0	(24,650)	0	(24,650)
Other comprehensive loss							0	0	(3,624)	0	0	(3,624)
Net income							$ 0	0	0	73,384	0	73,384
Balance (in shares) at Mar. 31, 2021							79,595,025
Ending balance, loss, net of tax at Mar. 31, 2021							$ 907	965,566	1,686	1,834,919	(342,131)	2,460,947
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)							21,415
Dividend Reinvestment Plan							$ 0	945	0	0	0	945
Restricted stock units vested (in shares)							10,908
Restricted stock units vested							$ 0	0	0	0	0	0
Shares withheld related to net share settlement of RSUs							$ 0	(285)	0	0	0	$ (285)
Purchases of treasury stock (in shares)							(704,927)					(704,927,000,000)
Purchases of treasury stock							$ 0	0	0	0	(32,896)	$ (32,896)
Stock-based compensation							0	1,614	0	0	0	1,614
Cash dividends							0	0	0	(25,515)	0	(25,515)
Other comprehensive loss							0	0	(42,912)	0	0	(42,912)
Net income							$ 0	0	0	75,028	0	75,028
Balance (in shares) at Mar. 31, 2022							75,078,258
Ending balance, loss, net of tax at Mar. 31, 2022							$ 909	$ 974,748	$ (45,977)	$ 2,034,681	$ (542,131)	$ 2,422,230