Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Valuation allowance on foreign deferred tax assets	$ 1,653	$ 1,392
Effective income tax rates	20.80%	50.90%	28.00%
Tax Cuts and Jobs Act of 2017, transition tax	$ 35,300
Impairment of deferred tax assets	13,200
Unrecognized tax benefits	1,588	$ 2,284	$ 2,691	$ 3,137
Unrecognized tax benefits, impact on effective tax rate	1,300
Settlements and lapsing of statutes of limitations within the next 12 months	1,600
Income tax penalties and interest accrued	200	$ 600
Foreign Operations
Operating Loss Carryforwards [Line Items]
Foreign net operating loss carryforwards	6,700
Valuation allowance on foreign net operating loss carryforwards	5,000
Valuation allowance on foreign deferred tax assets	500
Foreign Operations | Expiring Tax Period Between 2020 and 2036
Operating Loss Carryforwards [Line Items]
Foreign net operating loss carryforwards	$ 1,200