Fair Value Measurement Fair Value Inputs, Liabilities, Quantitative Information (Details)	Sep. 30, 2018	Dec. 31, 2017
MeasurementinputadjustedEBITDAvolatility [Domain]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.2500	0.2600
Measurement Input, Discount Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.0825	0.0875
Measurement Input, Risk Free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.0313	0.0258
Measurement Input, Price Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.0499	0.0599
Measurement Input, Cost of Debt [Domain]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.0474	0.0408