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Acquisition (Details 1) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
Acquisition (Details 1) - USD ($) $ in Millions	Jan. 04, 2019	Jun. 30, 2019	Dec. 31, 2018
Trade Names
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		11 years	10 years
Customer Lists
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		14 years	15 years
Gaomei
Business Acquisition [Line Items]
Business Acquisition, Name of Acquired Entity	Hefei Gaomei Cleaning Machines Co., Ltd. and Anhui Rongen Environmental Protection Technology Co., Ltd. (collectively "Gaomei")
Business Acquisition, Goodwill, Expected Tax Deductible Amount	$ 0.0
Recorded Unconditional Purchase Obligation		$ 11.3
Purchase Obligation, Due in Second Year		$ 11.3
Gaomei \| Minimum
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability	0.0
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		10 years
Gaomei \| Maximum
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability	42.4
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		15 years
Fair Value \| Contingent Consideration
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability	$ 4.5	$ 6.6