CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Capital Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Balance, beginning of period at Dec. 31, 2021		$ 18,730	$ 163,583	$ 981,825	$ (45,243)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for vested restricted stock units, net of shares withheld for taxes		68	(10,691)
Shares issued for employee stock purchase plan		6	944
Shares issued to directors		7	(7)
Equity compensation expense			8,056
Net income	$ 34,483			34,483
Other comprehensive income (loss)	(45,190)				(45,190)
Balance, end of period at Jun. 30, 2022	1,106,571	18,811	161,885	1,016,308	(90,433)
Balance, beginning of period at Mar. 31, 2022		18,803	157,164	998,425	(56,914)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for vested restricted stock units, net of shares withheld for taxes		1	(126)
Shares issued for employee stock purchase plan		0	0
Equity compensation expense			4,854
Net income	17,883			17,883
Other comprehensive income (loss)	(33,519)				(33,519)
Balance, end of period at Jun. 30, 2022	1,106,571	18,811	161,885	1,016,308	(90,433)
Balance, beginning of period at Dec. 31, 2022	1,172,466	18,574	140,702	1,098,454	(85,264)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for vested restricted stock units, net of shares withheld for taxes		35	(2,548)
Shares issued for employee stock purchase plan		0	0
Shares issued to directors		7	(7)
Equity compensation expense			7,072
Net income	14,359			14,359
Other comprehensive income (loss)	14,233				14,233
Balance, end of period at Jun. 30, 2023	1,205,617	18,616	145,219	1,112,813	(71,031)
Balance, beginning of period at Mar. 31, 2023		18,609	140,214	1,094,949	(75,514)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for vested restricted stock units, net of shares withheld for taxes		0	(7)
Shares issued for employee stock purchase plan		0	0
Equity compensation expense			5,019
Net income	17,864			17,864
Other comprehensive income (loss)	4,483				4,483
Balance, end of period at Jun. 30, 2023	$ 1,205,617	$ 18,616	$ 145,219	$ 1,112,813	$ (71,031)