Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Tax cuts and jobs act of 2017, incomplete accounting, change in tax rate, deferred tax asset, provisional income tax expense	$ 19,400
Tax cuts and jobs act of 2017, incomplete accounting, transition tax for accumulated foreign earnings, provisional income tax expense	17,400
Tax Cuts And Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit)	(2,000)
Deferred income tax assets, domestic	7,700	$ 7,800
Deferred income tax assets, foreign	7,900	6,400
Deferred tax assets, valuation allowance, noncurrent	1,631	876
Net increase (decrease) in total valuation allowance	$ (700)	$ (100)	$ 1,000
Minimum
Income Taxes [Line Items]
Deferred income tax assets, operating loss carryforwards expiration period	1 year
Tax returns examination statute of limitations period	3 years
Maximum
Income Taxes [Line Items]
Deferred income tax assets, operating loss carryforwards expiration period	9 years
Tax returns examination statute of limitations period	4 years