Consolidated Condensed Statements of Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Balance at period start (shares) at Dec. 31, 2021			31,299
Balance at period start at Dec. 31, 2021		$ 785,435	$ 313	$ 396,771	$ 496,605	$ (54,203)	$ (54,051)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee plans		6,252		2,232			4,020
Stock-based compensation		4,463		4,463
Dividends on common stock ($0.20 per share)		(5,899)			(5,899)
Comprehensive income:
Cash flow hedging gain, net						1,082
Pension liability, net of income tax						521
Foreign currency translation adjustments						(163)
Net income (loss)					14,975
Comprehensive income (loss)		$ 16,415
Accounting Standards Update [Extensible Enumeration]		Accounting Standards Update 2020-06
Balance at period end (shares) at Mar. 31, 2022			31,299
Balance at period end at Mar. 31, 2022		$ 789,546	$ 313	365,555	526,472	(52,763)	(50,031)
Balance at period end (Accounting Standards Update 2020-06) at Mar. 31, 2022	[1]	(17,120)		(37,911)	20,791
Balance at period start (shares) at Dec. 31, 2021			31,299
Balance at period start at Dec. 31, 2021		785,435	$ 313	396,771	496,605	(54,203)	(54,051)
Comprehensive income:
Cash flow hedging gain, net		5,744
Pension liability, net of income tax		1,012
Foreign currency translation adjustments		(9,661)
Net income (loss)		(153,316)
Comprehensive income (loss)		(156,221)
Balance at period end (shares) at Jun. 30, 2022			31,299
Balance at period end at Jun. 30, 2022		672,968	$ 313	401,182	352,089	(57,108)	(23,508)
Balance at period start (shares) at Mar. 31, 2022			31,299
Balance at period start at Mar. 31, 2022		789,546	$ 313	365,555	526,472	(52,763)	(50,031)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee plans		1,244		611			633
Stock-based compensation		5,755		5,755
Dividends on common stock ($0.20 per share)		(6,092)			(6,092)
Stock Issued During Period, Value, Conversion of Convertible Securities		0		(25,890)			25,890
Adjustments to Additional Paid in Capital, Convertible Note Premium on Extinguishment		103,125		103,125
Adjustments to Additional Paid in Capital, Settlement of Convertible Notes Hedge Transactions		118,912		118,912
Adjustments to Additional Paid in Capital, Warrant Settled		(96,758)		(96,758)
Adjustments to Additional Paid in Capital, Convertible Note Hedge, Net of Income Tax		(142,128)		(142,128)
Issuance of warrants		72,000		72,000
Comprehensive income:
Cash flow hedging gain, net		4,662				4,662
Pension liability, net of income tax		490				490
Foreign currency translation adjustments		(9,497)				(9,497)
Net income (loss)		(168,291)			(168,291)
Comprehensive income (loss)		(172,636)
Balance at period end (shares) at Jun. 30, 2022			31,299
Balance at period end at Jun. 30, 2022		672,968	$ 313	401,182	352,089	(57,108)	(23,508)
Balance at period start (shares) at Dec. 31, 2022			31,299
Balance at period start at Dec. 31, 2022		745,545	$ 313	413,235	412,631	(57,858)	(22,776)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee plans		2,600		556			2,044
Stock-based compensation		5,726		5,726
Dividends on common stock ($0.20 per share)		(6,113)			(6,113)
Comprehensive income:
Cash flow hedging gain, net						877
Pension liability, net of income tax						403
Foreign currency translation adjustments						1,596
Net income (loss)					1,819
Comprehensive income (loss)		4,695
Balance at period end (shares) at Mar. 31, 2023			31,299
Balance at period end at Mar. 31, 2023		752,453	$ 313	419,517	408,337	(54,982)	(20,732)
Balance at period start (shares) at Dec. 31, 2022			31,299
Balance at period start at Dec. 31, 2022		745,545	$ 313	413,235	412,631	(57,858)	(22,776)
Comprehensive income:
Cash flow hedging gain, net		1,381
Pension liability, net of income tax		806
Foreign currency translation adjustments		2,724
Net income (loss)		15,551
Comprehensive income (loss)		20,462
Balance at period end (shares) at Jun. 30, 2023			31,299
Balance at period end at Jun. 30, 2023		780,194	$ 313	432,780	415,924	(52,947)	(15,876)
Balance at period start (shares) at Mar. 31, 2023			31,299
Balance at period start at Mar. 31, 2023		752,453	$ 313	419,517	408,337	(54,982)	(20,732)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee plans		11,697		6,841			4,856
Stock-based compensation		6,422		6,422
Dividends on common stock ($0.20 per share)		(6,145)			(6,145)
Comprehensive income:
Cash flow hedging gain, net		503				503
Pension liability, net of income tax		403				403
Foreign currency translation adjustments		1,129				1,129
Net income (loss)		13,732			13,732
Comprehensive income (loss)		15,767
Balance at period end (shares) at Jun. 30, 2023			31,299
Balance at period end at Jun. 30, 2023		$ 780,194	$ 313	$ 432,780	$ 415,924	$ (52,947)	$ (15,876)

[1] (1)We recorded the cumulative impact of adopting Accounting Standards Update (ASU) 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity in 2022.