Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Intangible asset impairment charge	$ 2,702	$ 657	$ 3,250	$ 657
Impairment of other assets	196	0	829	86
Contingent Receivable | Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on contingent receivable	$ (119)	$ (167)	$ (101)	$ (299)
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Income [Extensible List]	us-gaap:BusinessCombinationContingentConsiderationArrangementsContingentConsiderationBenefit	us-gaap:BusinessCombinationContingentConsiderationArrangementsContingentConsiderationBenefit	us-gaap:BusinessCombinationContingentConsiderationArrangementsContingentConsiderationBenefit	us-gaap:BusinessCombinationContingentConsiderationArrangementsContingentConsiderationBenefit
Payment received on contingent receivable		$ 0		$ 153
Other long-term obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability, noncurrent	$ 72,500		$ 72,500		$ 58,500
Accrued expenses
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability, current	$ 7,100		$ 7,100		$ 23,800