Condensed Consolidated Statements of Stockholders' Deficit (Unaudited) - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2022		$ 378,200,000	$ 50,800,000	$ (514,600,000)	$ (85,600,000)
Balance, shares at Dec. 31, 2022	25,909,516
Foreign currency translation adjustments			(2,900,000)		(2,900,000)
Reclassification of loss on pension plan to comprehensive income			200,000		200,000
Issuances under stock plans
Issuances under stock plans, shares	353,554
Stock-based compensation expense		3,000,000.0			3,000,000.0
Net income (loss)				(1,400,000)	(1,400,000)
Reclassification of loss on hedging instrument to comprehensive income			200,000		200,000
Balance at Mar. 31, 2023		381,200,000	48,300,000	(516,000,000.0)	(86,500,000)
Balance, shares at Mar. 31, 2023	26,263,070
Balance at Dec. 31, 2022		378,200,000	50,800,000	(514,600,000)	(85,600,000)
Balance, shares at Dec. 31, 2022	25,909,516
Foreign currency translation adjustments					(2,000,000.0)
Net income (loss)					7,600,000
Balance at Sep. 30, 2023		386,300,000	49,800,000	(508,600,000)	(72,500,000)
Balance, shares at Sep. 30, 2023	26,214,739
Balance at Mar. 31, 2023		381,200,000	48,300,000	(516,000,000.0)	(86,500,000)
Balance, shares at Mar. 31, 2023	26,263,070
Foreign currency translation adjustments			(2,700,000)		(2,700,000)
Reclassification of loss on pension plan to comprehensive income			300,000		300,000
Issuances under stock plans		(200,000)			(200,000)
Issuances under stock plans, shares	4,282
Stock-based compensation expense		3,100,000			3,100,000
Net income (loss)				5,600,000	5,600,000
Reclassification of loss on hedging instrument to comprehensive income			100,000		100,000
Repurchase of common stock				(100,000)	(100,000)
Repurchase of common stock, shares	(3,931)
Balance at Jun. 30, 2023		384,100,000	46,000,000.0	(510,500,000)	(80,400,000)
Balance, shares at Jun. 30, 2023	26,263,421
Foreign currency translation adjustments			3,600,000		3,600,000
Reclassification of loss on pension plan to comprehensive income			200,000		200,000
Issuances under stock plans		(1,100,000)			(1,100,000)
Issuances under stock plans, shares	73,165
Stock-based compensation expense		3,300,000			3,300,000
Net income (loss)				3,400,000	3,400,000
Repurchase of common stock				(1,500,000)	(1,500,000)
Repurchase of common stock, shares	(121,847)
Balance at Sep. 30, 2023		386,300,000	49,800,000	(508,600,000)	(72,500,000)
Balance, shares at Sep. 30, 2023	26,214,739
Balance at Dec. 31, 2023		386,100,000	44,500,000	(508,600,000)	(78,000,000.0)
Balance, shares at Dec. 31, 2023	26,219,021
Foreign currency translation adjustments			1,000,000.0		1,000,000.0
Reclassification of loss on pension plan to comprehensive income			300,000		300,000
Issuances under stock plans		(800,000)			(800,000)
Issuances under stock plans, shares	340,735
Stock-based compensation expense		2,000,000.0			2,000,000.0
Net income (loss)				(5,700,000)	(5,700,000)
Balance at Mar. 31, 2024		387,300,000	45,800,000	(514,300,000)	(81,200,000)
Balance, shares at Mar. 31, 2024	26,559,756
Balance at Dec. 31, 2023		386,100,000	44,500,000	(508,600,000)	(78,000,000.0)
Balance, shares at Dec. 31, 2023	26,219,021
Foreign currency translation adjustments					(5,500,000)
Net income (loss)					(300,000)
Balance at Sep. 30, 2024		390,700,000	39,900,000	(508,900,000)	(78,300,000)
Balance, shares at Sep. 30, 2024	26,574,804
Balance at Mar. 31, 2024		387,300,000	45,800,000	(514,300,000)	(81,200,000)
Balance, shares at Mar. 31, 2024	26,559,756
Foreign currency translation adjustments			(200,000)		(200,000)
Reclassification of loss on pension plan to comprehensive income			300,000		300,000
Issuances under stock plans
Issuances under stock plans, shares	11,552
Stock-based compensation expense		1,700,000			1,700,000
Net income (loss)				2,000,000.0	2,000,000.0
Balance at Jun. 30, 2024		389,000,000.0	45,900,000	(512,300,000)	(77,400,000)
Balance, shares at Jun. 30, 2024	26,571,308
Foreign currency translation adjustments			(6,300,000)		(6,300,000)
Reclassification of loss on pension plan to comprehensive income			300,000		300,000
Issuances under stock plans
Issuances under stock plans, shares	3,496
Stock-based compensation expense		1,700,000			1,700,000
Net income (loss)				3,400,000	3,400,000
Balance at Sep. 30, 2024		$ 390,700,000	$ 39,900,000	$ (508,900,000)	$ (78,300,000)
Balance, shares at Sep. 30, 2024	26,574,804