Discontinued Operations and Special Charges (Gains) - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of business		$ 0.0	$ 178.2	$ 0.0	$ 178.2
Special charges, net		(0.8)	0.9	(0.8)	0.9
Discontinued Operations - Disposed of by Sale | NATG
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Vendor settlements				0.2	0.1
Professional costs related to restitution proceedings			(0.1)	0.1	0.1
Additional charges				1.0
Restitution receipts			0.3		1.0
Lease reserve adjustment			1.8		1.7
Discontinued Operations - Disposed of by Sale | SARL Businesses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow funds					0.2
Accelerated depreciation					0.1
Legal, professional, and other costs					0.1
Disposal Group, Disposed of by Sale, Not Discontinued Operations | France Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of business	$ 178.2
Proceeds from sale of business	267.3		267.3		267.3
Net assets sold	82.5		82.5		82.5
Accelerated amortization expense of restricted stock units and stock options	1.5		1.5		1.5
Deal transaction costs related to sale	$ 5.1		5.1		5.1
NATG | Restatement Adjustment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reclassification of restructuring reserve						$ 3.4
ETG - Discontinued | Disposal Group, Disposed of by Sale, Not Discontinued Operations | France Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of business			178.2		178.2
GERMANY
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain related to change in estimate of outstanding lease obligation		$ 0.8		$ 0.8
Continuing Operations | NATG
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Special charges, net			0.8		0.8
Continuing Operations | GERMANY
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Special charges, net			$ 0.1		$ 0.1