Commitments and Contingencies (Details)	6 Months Ended
	Jun. 30, 2019 USD ($) claim	Dec. 31, 2018 USD ($)
Value-added tax assessments and other civil litigation
Commitments and contingencies
Minimum number of claims that the Company's insurance coverage may not be sufficient to cover | claim	1
Provision for losses	$ 0
Non-Income Tax Contingencies
Commitments and contingencies
Accrued liabilities	300,000	$ 300,000
Minimum | Value-added tax assessments and other civil litigation
Commitments and contingencies
Estimate of possible loss	0
Minimum | Non-Income Tax Contingencies
Commitments and contingencies
Estimate of possible loss	0
Maximum | Value-added tax assessments and other civil litigation
Commitments and contingencies
Estimate of possible loss	400,000
Maximum | Non-Income Tax Contingencies
Commitments and contingencies
Estimate of possible loss	3,500,000
Pending Litigation
Commitments and contingencies
Accrued liabilities	$ 2,000,000	$ 1,700,000