Debt - Components of Debt Obligations and Weighted Average Interest Rate (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Unaccreted discount and issuance costs	$ (212)	$ (324)
Short-term debt	14,822	0
Finance lease liability	118	189
Total long-term debt	29,797	33,883
Current portion of long-term debt	3,015	3,232
Long-term debt, net of current portion	26,570	30,327
Total long-term debt, net of unaccreted discount and issuance costs	29,585	33,559
Line of credit | Note payable to Shanghai Pudong Development Bank
Debt Instrument [Line Items]
Note payable to Shanghai Pudong Development Bank	15,000	0
Unaccreted discount and issuance costs	(178)	0
Short-term debt	$ 14,822	$ 0
Weighted average interest rate	0.60%	0.00%
Line of credit | Borrowing under Wells Fargo Credit Facility
Debt Instrument [Line Items]
Weighted average interest rate	1.90%	2.01%
Long-term debt, gross	$ 20,241	$ 21,030
Notes payable to banks | Mitsubishi Bank loans
Debt Instrument [Line Items]
Long-term debt, gross	$ 5,633	$ 7,662
Notes payable to banks | Mitsubishi Bank loans | Minimum
Debt Instrument [Line Items]
Weighted average interest rate	1.07%	1.05%
Notes payable to banks | Mitsubishi Bank loans | Maximum
Debt Instrument [Line Items]
Weighted average interest rate	1.47%	1.45%
Notes payable to banks | Mitsubishi Bank and Yamanashi Chuo Bank loan
Debt Instrument [Line Items]
Weighted average interest rate	1.07%	1.07%
Long-term debt, gross	$ 3,805	$ 5,002