Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Examination [Line Items]
U.S. federal income tax rate, percent		35.00%	35.00%	35.00%
Tax cuts and jobs act description		On December 22, 2017, the U.S. government enacted the Tax Cuts and Jobs Act (“Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code that affected 2017, including, but not limited to, (1) requiring a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries that is payable over eight years and (2) bonus depreciation that will allow for full expensing of qualified property. The Tax Act also establishes new tax laws that will affect 2018, including, but not limited to, (1) reduction of the U.S. federal corporate tax rate; (2) the creation of the Base Erosion and Anti-Abuse (“BEAT”), a new minimum tax; (3) a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries; (4) a new provision designed to tax Global Intangible Low-Taxed Income (“GILTI”), which allows for the possibility of using FTCs and a deduction of up to 50 percent to offset the income tax liability (subject to some limitations); (5) the repeal of the domestic production activity deduction; (6) limitations on the deductibility of certain executive compensation; and (7) limitations on the use of FTCs to reduce the U.S. income tax liability. Given the complexity of the 2018 Tax Act provisions identified above, we are still evaluating the effects and have not yet determined what, if any, accounting policies will need to change, nor have we calculated the impact of the above provisions.
Remeasurement of deferred		$ 8,020
Adjustment to deferred income tax expense		8,000
Transition tax expense		1,500
Section 78 FTC		1,500
Tax reform FTC valuation allowance		1,500
Deferred tax assets, valuation allowance		2,447	$ 1,924
Operating loss carryforward, federal		591
Operating loss carryforward, state		171
Operating loss carryforward, foreign		1,134
Federal RD credit carryforward		118
State RD Credit Carryforward		318
Foreign RD credit carryforward		1,542
Undistributed earnings of foreign subsidiaries		7,663
Unrecognized tax benefit adjustment to income tax expense		4,403	4,275
Unrecognized tax benefits, income tax penalties and interest expense		246	76	$ 71
Unrecognized tax benefits, income tax penalties and interest accrued		$ 1,190	$ 1,019
Federal [Member]
Income Tax Examination [Line Items]
Operating loss carryforwards expiration date		Dec. 31, 2032
Federal [Member] | Research and Development Credit [Member]
Income Tax Examination [Line Items]
Tax credit carryforward expiration date		Dec. 31, 2037
State [Member]
Income Tax Examination [Line Items]
Operating loss carryforwards expiration date		Dec. 31, 2032
State [Member] | Research and Development Credit [Member]
Income Tax Examination [Line Items]
Tax credit carryforward expiration date		Dec. 21, 2024
Foreign [Member]
Income Tax Examination [Line Items]
Operating loss carryforwards expiration date		Dec. 31, 2026
Foreign [Member] | Research and Development Credit [Member]
Income Tax Examination [Line Items]
Tax credit carryforward expiration date		Dec. 31, 2027
Forecast [Member]
Income Tax Examination [Line Items]
U.S. federal income tax rate, percent	21.00%