Debt - Components of Debt Obligations and Weighted Average Interest Rate (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, gross and lease obligation	$ 41,015	$ 42,452
Finance lease liability	254	275
Unaccreted discount and issuance costs	(412)	(446)
Current portion of long-term debt	3,066	3,044
Long-term debt, net of current portion	37,791	39,237
Total long-term debt, net of unaccreted discount and issuance costs	40,857	42,281
Line of Credit \| Wells Fargo Credit Facility
Debt Instrument [Line Items]
Long-term debt, gross and lease obligation	$ 26,596	$ 27,329
Weighted average interest rate	2.93%	3.72%
Line of Credit \| Mitsubishi Bank Loans \| Minimum
Debt Instrument [Line Items]
Weighted average interest rate	1.05%	1.04%
Line of Credit \| Mitsubishi Bank Loans \| Maximum
Debt Instrument [Line Items]
Weighted average interest rate	1.45%	1.44%
Notes Payable to Banks \| Mitsubishi Bank Loans
Debt Instrument [Line Items]
Long-term debt, gross and lease obligation	$ 8,803	$ 9,255
Notes Payable to Banks \| Mitsubishi Bank Loans And Yamanashi Chuo Bank Loans
Debt Instrument [Line Items]
Long-term debt, gross and lease obligation	$ 5,616	$ 5,868
Weighted average interest rate	1.07%	1.07%

Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Current, Net

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- Definition

Long-term Debt, Gross And Lease Obligation

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

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- Definition

Amount of long-term debt and lease obligation, classified as noncurrent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount of long-term debt and lease obligation, classified as current.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount of long-term debt and lease obligation, including portion classified as current.

+ References

No definition available.

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