Bank Borrowing (Details)							1 Months Ended							3 Months Ended
	Mar. 31, 2020 CNY (¥)	Mar. 31, 2020 USD ($)	Aug. 09, 2019 USD ($)	Mar. 12, 2019 CNY (¥)	May 09, 2018 CNY (¥)	Aug. 15, 2017 USD ($)	Feb. 29, 2020 USD ($)	Jan. 31, 2020 USD ($)	Dec. 31, 2019 CNY (¥)	Oct. 31, 2019 CNY (¥)	Mar. 31, 2019 CNY (¥)	Jul. 31, 2018 USD ($)	Jan. 31, 2018 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Oct. 31, 2019 USD ($)	Sep. 23, 2019 CNY (¥)	Sep. 23, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Mar. 21, 2019 CNY (¥) Rate	Mar. 12, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 04, 2018 CNY (¥)	Nov. 29, 2018 CNY (¥)	Nov. 16, 2018 CNY (¥)	Nov. 16, 2018 USD ($)	May 09, 2018 USD ($)	May 01, 2018 USD ($)
Debt Instrument [Line Items]
Restricted cash															$ 4,300,000					$ 2,400,000
Maturities of debt
2020 (Remaining)															9,648,000
2020															28,641,000
2021															20,022,000
2022															28,511,000
2023															12,082,000
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five															8,881,000
Total principal of debts															107,785,000
Less: debt issuance costs															(768,000)
Total principal of debt, less debt issuance costs															107,017,000
Long-term Debt, Current Maturities															32,812,000					26,609,000
Long-term Debt, Excluding Current Maturities															74,205,000					$ 59,380,000
Long-term Debt, Current Maturities, And Short-Term Debt, Gross															33,099,000
Long-term Debt, Excluding Current Maturities, Gross															74,686,000
Debt Issuance Costs, Gross, Current															(287,000)
Debt Issuance Cost, Gross, Noncurrent															(481,000)
Long-term Debt, Current Maturities, And Short-term Debt															32,812,000
Term Loan | Secured Debt | Variable Interest Rate Term Loan Maturing August 2022
Debt Instrument [Line Items]
Debt instrument, term					5 years	5 years
Bank Of Communications Limited
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity										¥ 60,000,000.0							$ 8,500,000
Loan agreements, short-term debt															0
China Merchant Bank And Chongqing LiangJiang New District China Merchants Group Limited Company | Loan Agreement November 29 2018
Debt Instrument [Line Items]
Debt instrument, face amount | ¥																										¥ 80,000,000
China Merchant Bank And Chongqing LiangJiang New District China Merchants Group Limited Company | Loan Agreement December 4 2018
Debt Instrument [Line Items]
Debt instrument, face amount | ¥																									¥ 20,000,000
China Merchant Bank And Chongqing LiangJiang New District China Merchants Group Limited Company | Loan Agreements November 29 And December 4 2018
Debt Instrument [Line Items]
Debt instrument, face amount																								$ 14,500,000
Loan agreements, short-term debt															14,100,000
Hongkong And Shanghai Banking Corporation Limited [Member] | Secured Debt | Accounts Receivable Factoring Agreement August 9 2019
Debt Instrument [Line Items]
Accounts Receivable Factoring Agreement, Amount Borrowed														$ 8,000,000
Accounts receivable factoring agreement, maximum borrowing capacity, percent of net accounts receivable			70.00%
Accounts receivable factoring agreement, maximum borrowing capacity			$ 30,000,000.0
Accounts receivable factoring agreement, remaining borrowing capacity															30,000,000.0
Basis spread on variable rate			1.75%
Repayments of accounts receivable factoring agreement														$ 8,000,000.0
Accounts receivable factoring agreement, borrowed amount outstanding															0
YinHai Leasing Company and China Import/Export Bank | Lease Financing
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					¥ 400,000,000.0																								$ 62,800,000
Nominal sale amount at end of lease term | ¥					¥ 1
Amount outstanding	¥ 325,000,000.0														45,800,000
China Development Bank | Secured Debt
Debt Instrument [Line Items]
Debt instrument, face amount																$ 24,000,000.0
Basis spread on variable rate									2.80%
Long-term debt															24,000,000.0
China Development Bank | London Interbank Offered Rate (LIBOR) | Secured Debt
Debt Instrument [Line Items]
Basis spread on variable rate									2.80%
Export-Import Bank Of China
Debt Instrument [Line Items]
Restricted cash				¥ 14,000,000																			$ 2,000,000.0
Line of credit facility outstanding balance	¥ 197,000,000	$ 27,800,000
Export-Import Bank Of China | Secured Debt
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity				¥ 200,000,000																			$ 29,800,000
Proceeds from lines of credit | ¥									¥ 10,000,000		¥ 190,000,000
Repayments of Lines of Credit | ¥									¥ 3,000,000.0
Maturities of debt
Line Of Credit Facility, Interest Rate During Period, China Base Rate Multiplier				1.1
Line of Credit Facility, Interest Rate During Period				5.39%
The Bank | Secured Debt
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity																														$ 17,800,000
Amount outstanding															16,200,000
Stated percentage																														5.04%
The Bank | Term Loan | Secured Debt | Variable Interest Rate Term Loan Maturing August 2022
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity						$ 30,000,000.0
Amount outstanding															18,600,000
Proceeds from lines of credit												$ 16,700,000	$ 13,200,000
The Bank | Minimum | London Interbank Offered Rate (LIBOR) | Term Loan | Secured Debt | Variable Interest Rate Term Loan Maturing August 2022
Debt Instrument [Line Items]
Basis spread on variable rate						1.75%
The Bank | Maximum | London Interbank Offered Rate (LIBOR) | Term Loan | Secured Debt | Variable Interest Rate Term Loan Maturing August 2022
Debt Instrument [Line Items]
Basis spread on variable rate						2.25%
China | Bank Of Communications Limited | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate, multiple										1.05							1.05
Basis spread on variable rate										4.99%
China | YinHai Leasing Company and China Import/Export Bank | Base Rate | Lease Financing
Debt Instrument [Line Items]
Basis spread on variable rate, multiple					1.15																								1.15
Basis spread on variable rate					5.4625%
Foreign Line of Credit | China Everbright Bank | Loan Agreement September 23 2019
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity																		¥ 50,000,000.0	$ 7,100,000
Line of credit facility, amount drawn							$ 5,500,000	$ 1,600,000
Loan agreements, short-term debt															7,100,000
Foreign Line of Credit | Industrial And Commercial Bank of China
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity																											¥ 72,000,000.0	$ 10,300,000
Loan agreements, short-term debt															0
Loans Payable | China Everbright Bank | Loan Agreement March 21 2019
Debt Instrument [Line Items]
Debt instrument, face amount																					$ 3,000,000.0	¥ 20,000,000
Loan agreements, short-term debt															$ 0
Short-term debt, fixed interest rate | Rate																						5.44%