Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common stock	Retained earnings	Accumulated other comprehensive income (loss)
Beginning balance (in shares) at Dec. 31, 2020		109,181,000
Beginning balance at Dec. 31, 2020	$ 2,337,502	$ 1,678,368	$ 660,398	$ (1,264)
Increase (decrease) in stockholders' equity
Net income for common stock	64,358		64,358
Other comprehensive income (loss), net of tax benefits	(44,016)			(44,016)
Share-based expenses and other, net (in shares)		100,000
Share-based expenses and other, net	605	$ 605
Common stock dividends	(37,156)		(37,156)
Ending balance (in shares) at Mar. 31, 2021		109,281,000
Ending balance at Mar. 31, 2021	2,321,293	$ 1,678,973	687,600	(45,280)
Beginning balance (in shares) at Dec. 31, 2020		109,181,000
Beginning balance at Dec. 31, 2020	2,337,502	$ 1,678,368	660,398	(1,264)
Increase (decrease) in stockholders' equity
Net income for common stock	128,230
Other comprehensive income (loss), net of tax benefits	(27,544)
Ending balance (in shares) at Jun. 30, 2021		109,311,000
Ending balance at Jun. 30, 2021	2,367,329	$ 1,681,820	714,317	(28,808)
Beginning balance (in shares) at Mar. 31, 2021		109,281,000
Beginning balance at Mar. 31, 2021	2,321,293	$ 1,678,973	687,600	(45,280)
Increase (decrease) in stockholders' equity
Net income for common stock	63,872		63,872
Other comprehensive income (loss), net of tax benefits	16,472			16,472
Share-based expenses and other, net (in shares)		30,000
Share-based expenses and other, net	2,847	$ 2,847
Common stock dividends	(37,155)		(37,155)
Ending balance (in shares) at Jun. 30, 2021		109,311,000
Ending balance at Jun. 30, 2021	$ 2,367,329	$ 1,681,820	714,317	(28,808)
Beginning balance (in shares) at Dec. 31, 2021	109,311,785	109,312,000
Beginning balance at Dec. 31, 2021	$ 2,390,884	$ 1,685,496	757,921	(52,533)
Increase (decrease) in stockholders' equity
Net income for common stock	69,167		69,167
Other comprehensive income (loss), net of tax benefits	(117,159)			(117,159)
Share-based expenses and other, net (in shares)		119,000
Share-based expenses and other, net	(949)	$ (949)
Common stock dividends	(38,301)		(38,301)
Ending balance (in shares) at Mar. 31, 2022		109,431,000
Ending balance at Mar. 31, 2022	$ 2,303,642	$ 1,684,547	788,787	(169,692)
Beginning balance (in shares) at Dec. 31, 2021	109,311,785	109,312,000
Beginning balance at Dec. 31, 2021	$ 2,390,884	$ 1,685,496	757,921	(52,533)
Increase (decrease) in stockholders' equity
Net income for common stock	121,708
Other comprehensive income (loss), net of tax benefits	$ (204,999)
Ending balance (in shares) at Jun. 30, 2022	109,466,829	109,467,000
Ending balance at Jun. 30, 2022	$ 2,233,504	$ 1,688,009	803,027	(257,532)
Beginning balance (in shares) at Mar. 31, 2022		109,431,000
Beginning balance at Mar. 31, 2022	2,303,642	$ 1,684,547	788,787	(169,692)
Increase (decrease) in stockholders' equity
Net income for common stock	52,541		52,541
Other comprehensive income (loss), net of tax benefits	(87,840)			(87,840)
Share-based expenses and other, net (in shares)		36,000
Share-based expenses and other, net	3,462	$ 3,462
Common stock dividends	$ (38,301)		(38,301)
Ending balance (in shares) at Jun. 30, 2022	109,466,829	109,467,000
Ending balance at Jun. 30, 2022	$ 2,233,504	$ 1,688,009	$ 803,027	$ (257,532)