Fair Value Measurements (Details 4) $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration liability, current	$ 0.7
Contingent consideration liability, noncurrent	0.8
The Melton Corporation [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration settled, transferred out of fair value (Level 3)	$ 0.2