Condensed Consolidated Statements of Stockholders' Deficit - USD ($) $ in Millions	Common stock	Additional paid in capital	Accumulated other comprehensive income	Accumulated deficit	Total
Balance at Dec. 31, 2018		$ 329.9	$ 55.9	$ (404.2)	$ (18.4)
Balance (in Shares) at Dec. 31, 2018	20,870,397
Foreign currency translation adjustments			(0.5)		0.5
Actuarial gains (losses) on pension plan			0.9		0.9
Change in fair value of hedging instrument			(2.1)		(2.1)
Reclassification of loss on hedging instrument to comprehensive income			1.5		1.5
Shares issued in earnout		8.6			8.6
Shares issued in earnout (in Shares)	1,323,558
Stock-based compensation expense		1.7			1.7
Net loss				(5.0)	(5.0)
Balance at Mar. 31, 2019		340.2	55.7	(409.2)	(13.3)
Balance (in Shares) at Mar. 31, 2019	22,193,955
Balance at Dec. 31, 2018		329.9	55.9	(404.2)	(18.4)
Balance (in Shares) at Dec. 31, 2018	20,870,397
Foreign currency translation adjustments					0.2
Actuarial gains (losses) on pension plan					(1.1)
Reclassification of loss on hedging instrument to comprehensive income					(1.1)
Net loss					(15.7)
Balance at Jun. 30, 2019		343.1	54.2	(419.9)	(22.6)
Balance (in Shares) at Jun. 30, 2019	22,193,955
Balance at Mar. 31, 2019		340.2	55.7	(409.2)	(13.3)
Balance (in Shares) at Mar. 31, 2019	22,193,955
Foreign currency translation adjustments			0.7		0.7
Actuarial gains (losses) on pension plan			(2.0)		(2.0)
Change in fair value of hedging instrument			2.4		2.4
Reclassification of loss on hedging instrument to comprehensive income			(2.6)		(2.6)
Conversion of awards previously classified as derivatives		0.8			0.8
Stock-based compensation expense		2.1			2.1
Net loss				(10.7)	(10.7)
Balance at Jun. 30, 2019		343.1	54.2	(419.9)	(22.6)
Balance (in Shares) at Jun. 30, 2019	22,193,955
Balance at Dec. 31, 2019		346.6	45.1	(441.2)	(49.5)
Balance (in Shares) at Dec. 31, 2019	22,230,768
Foreign currency translation adjustments			3.1		3.1
Actuarial gains (losses) on pension plan			4.4		4.4
Change in fair value of hedging instrument			(1.5)		(1.5)
Reclassification of loss on hedging instrument to comprehensive income			0.4		0.4
Shares issued in net settlement of RSUs
Shares issued in net settlement of RSUs (in Shares)	166,959
Stock-based compensation expense		1.0			1.0
Net loss				(17.4)	(17.4)
Balance at Mar. 31, 2020		347.6	51.5	(458.6)	(59.5)
Balance (in Shares) at Mar. 31, 2020	22,397,727
Balance at Dec. 31, 2019		346.6	45.1	(441.2)	(49.5)
Balance (in Shares) at Dec. 31, 2019	22,230,768
Foreign currency translation adjustments					3.5
Actuarial gains (losses) on pension plan					(4.3)
Reclassification of loss on hedging instrument to comprehensive income					0.7
Net loss					(41.9)
Balance at Jun. 30, 2020		348.6	42.7	(483.1)	(91.8)
Balance (in Shares) at Jun. 30, 2020	22,405,376
Balance at Mar. 31, 2020		347.6	51.5	(458.6)	(59.5)
Balance (in Shares) at Mar. 31, 2020	22,397,727
Foreign currency translation adjustments			0.4		0.4
Actuarial gains (losses) on pension plan			(8.7)		(8.7)
Change in fair value of hedging instrument			(0.8)		(0.8)
Reclassification of loss on hedging instrument to comprehensive income			0.3		0.3
Stock-based compensation expense – ESPP
Stock-based compensation expense – ESPP (in Shares)	7,649
Stock-based compensation expense		1.0			1.0
Net loss				(24.5)	(24.5)
Balance at Jun. 30, 2020		$ 348.6	$ 42.7	$ (483.1)	$ (91.8)
Balance (in Shares) at Jun. 30, 2020	22,405,376