Bank Borrowing (Details) | Sep. 30, 2020CNY (¥)Rate | Sep. 30, 2020USD ($) | Jun. 28, 2020 | Jun. 24, 2020 | Apr. 26, 2020CNY (¥) | Sep. 23, 2019CNY (¥) | Aug. 09, 2019USD ($) | Mar. 12, 2019CNY (¥) | May 09, 2018CNY (¥) | May 01, 2018USD ($) | Aug. 15, 2017USD ($) | Apr. 30, 2020CNY (¥) | Apr. 30, 2020USD ($) | Dec. 31, 2019CNY (¥) | Oct. 31, 2019CNY (¥) | Mar. 31, 2019CNY (¥) | Jul. 31, 2018USD ($) | Jan. 31, 2018USD ($) | Sep. 30, 2020USD ($) | Jun. 30, 2020CNY (¥) | Jun. 30, 2020USD ($)Rate | Dec. 31, 2019CNY (¥) | Sep. 30, 2020USD ($)Rate | Apr. 26, 2020USD ($) | Apr. 15, 2020CNY (¥) | Apr. 15, 2020USD ($) | Dec. 31, 2019USD ($) | Oct. 31, 2019USD ($) | Sep. 23, 2019USD ($) | Mar. 12, 2019USD ($) | Dec. 31, 2018USD ($) | Dec. 04, 2018CNY (¥) | Nov. 29, 2018CNY (¥) | Nov. 16, 2018CNY (¥) | Nov. 16, 2018USD ($) | May 09, 2018USD ($) |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Restricted cash | | | | | | | | | | | | | | | | | | | | | $ 4,200,000 | | $ 4,300,000 | | | | | | | | | | | | | |
Maturities of debt | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
2021 (Remaining) | | | | | | | | | | | | | | | | | | | | | | | 31,157,000 | | | | | | | | | | | | | |
2022 | | | | | | | | | | | | | | | | | | | | | | | 26,890,000 | | | | | | | | | | | | | |
2023 | | | | | | | | | | | | | | | | | | | | | | | 37,579,000 | | | | | | | | | | | | | |
2024 | | | | | | | | | | | | | | | | | | | | | | | 23,352,000 | | | | | | | | | | | | | |
2025 | | | | | | | | | | | | | | | | | | | | | | | 15,017,000 | | | | | | | | | | | | | |
Total principal of debts | | | | | | | | | | | | | | | | | | | | | | | 133,995,000 | | | | | | | | | | | | | |
Less: debt issuance costs | | | | | | | | | | | | | | | | | | | | | | | (1,279,000) | | | | | | | | | | | | | |
Total principal of debt, less debt issuance costs | | | | | | | | | | | | | | | | | | | | | | | 132,716,000 | | | | | | | | | | | | | |
Long-term Debt, Current Maturities | | | | | | | | | | | | | | | | | | | | | 30,114,000 | | 32,746,000 | | | | | | | | | | | | | |
Long-term Debt, Excluding Current Maturities | | | | | | | | | | | | | | | | | | | | | 99,775,000 | | 99,970,000 | | | | | | | | | | | | | |
Long-term Debt, Current Maturities, And Short-Term Debt, Gross | | | | | | | | | | | | | | | | | | | | | | | 33,243,000 | | | | | | | | | | | | | |
Long-term Debt, Excluding Current Maturities, Gross | | | | | | | | | | | | | | | | | | | | | | | 100,752,000 | | | | | | | | | | | | | |
Debt Issuance Costs, Gross, Current | | | | | | | | | | | | | | | | | | | | | | | (497,000) | | | | | | | | | | | | | |
Debt Issuance Cost, Gross, Noncurrent | | | | | | | | | | | | | | | | | | | | | | | (782,000) | | | | | | | | | | | | | |
Long-term Debt, Current Maturities, And Short-term Debt | | | | | | | | | | | | | | | | | | | | | | | 32,746,000 | | | | | | | | | | | | | |
Bank Of Communications Limited | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Loan agreements, short-term debt | | | | | | | | | | | | | | | | | | | | | | | 0 | | | | | | | | | | | | | |
Line of credit facility, maximum borrowing capacity | | | | | | | | | | | | | | | ¥ 60,000,000 | | | | | | | | | | | | | $ 8,500,000 | | | | | | | | |
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 | | | | | | | | | | | | | | | | | | | | | | | 0 | | | | | | | | | | | | | |
Hongkong And Shanghai Banking Corporation Limited | Secured Debt | Accounts Receivable Factoring Agreement August 9 2019 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Accounts receivable factoring agreement, maximum borrowing capacity, percent of net accounts receivable | | | | | | | 70.00% | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Accounts receivable factoring agreement, maximum borrowing capacity | | | | | | | $ 30,000,000 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Accounts receivable factoring agreement, remaining borrowing capacity | | | | | | | | | | | | | | | | | | | | | | | 30,000,000 | | | | | | | | | | | | | |
Basis spread on variable rate | | | | | | | 1.75% | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from accounts receivable factoring agreement | | | | | | | | | | | | | | | | | | | $ 29,700,000 | | | | | | | | | | | | | | | | | |
Repayments of accounts receivable factoring agreement | | | | | | | | | | | | | | | | | | | 29,700,000 | | | | | | | | | | | | | | | | | |
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 | | | | | | | | | | | | | | | | | | | | | | | | | | | $ 62,800,000 |
Debt instrument, term | | | | | | | | | 5 years | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Nominal sale amount at end of lease term | ¥ | | | | | | | | | ¥ 1 | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Amount outstanding | ¥ 271,000,000 | | | | | | | | | | | | | | | | | | | | | | 39,800,000 | | | | | | | | | | | | | |
YinHai Leasing Company and China Import/Export Bank | China Five-Year Loan Prime Rate | Lease Financing | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Basis spread on variable rate | | | 0.8125% | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument effective interest rate | | | 5.4625% | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
China Development Bank | Secured Debt | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt instrument, face amount | | | | | | | | | | | | | | | | | | | | | | | | | | | $ 24,000,000 | | | | | | | | | |
Long-term debt | | | | | | | | | | | | | | | | | | | | | | | 24,000,000 | | | | | | | | | | | | | |
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 | | | | | | |
Line of credit facility outstanding balance | ¥ 194,000,000 | $ 28,500,000 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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 | ¥ | | | | | | | | | | | | | | | | | | | | | | ¥ 6,000,000 | | | | | | | | | | | | | | |
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% | | | | 5.39% | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Export-Import Bank Of China | China Five-Year Loan Prime Rate | Secured Debt | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Basis spread on variable rate | | | | 0.74% | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
China Development Bank, Agricultural Bank of China, China Merchant Bank and Chongqing Rural Commercial Bank [Member] | Secured Debt | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Line of credit facility, maximum borrowing capacity | | | | | ¥ 250,000,000 | | | | | | | | | | | | | | | | | | | $ 35,700,000 | | | | | | | | | | | | |
Amount outstanding | | | | | | | | | | | | | | | | | | | | | | | 36,700,000 | | | | | | | | | | | | | |
Proceeds from lines of credit | | | | | | | | | | | | ¥ 250,000,000 | $ 35,300,000 | | | | | | | | | | | | | | | | | | | | | | | |
China Development Bank, Agricultural Bank of China, China Merchant Bank and Chongqing Rural Commercial Bank [Member] | China One-Year Loan Prime Rate | Secured Debt | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Basis spread on variable rate | | | | | 1.30% | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
The Bank | Secured Debt | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Line of credit facility, maximum borrowing capacity | | | | | | | | | | $ 17,800,000 | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt instrument, term | | | | | | | | | | 5 years | | | | | | | | | | | | | | | | | | | | | | | | | | |
Amount outstanding | | | | | | | | | | | | | | | | | | | | | | | 15,700,000 | | | | | | | | | | | | | |
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 | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt instrument, term | | | | | | | | | | | 5 years | | | | | | | | | | | | | | | | | | | | | | | | | |
Amount outstanding | | | | | | | | | | | | | | | | | | | | | | | 14,900,000 | | | | | | | | | | | | | |
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] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Loan agreements, short-term debt | | | | | | | | | | | | | | | | | | | | | | | 0 | | | | | | | | | | | | | |
Line of credit facility, maximum borrowing capacity | | | | | | ¥ 50,000,000 | | | | | | | | | | | | | | | | | | | | | | | $ 7,100,000 | | | | | | | |
Period after borrowing date interest and principal payments due | | | | | | 90 days | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Foreign Line of Credit | Industrial And Commercial Bank of China | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Loan agreements, short-term debt | | | | | | | | | | | | | | | | | | | | | | | 0 | | | | | | | | | | | | | |
Line of credit facility, maximum borrowing capacity | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ¥ 72,000,000 | $ 10,300,000 | |
Loans Payable | Loan Agreement April 15, 2020 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt instrument, face amount | | | | | | | | | | | | | | | | | | | | | | | | | ¥ 100,000,000 | $ 14,300,000 | | | | | | | | | | |
Loan agreements, short-term debt | | | | | | | | | | | | | | | | | | | | | | | $ 14,200,000 | | | | | | | | | | | | | |
Loans Payable | Loan Agreement, April 15, 2020, Working Capital Borrowing In Chinese Yuan | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt instrument, face amount | ¥ | | | | | | | | | | | | | | | | | | | | | | | | | 20,000,000 | | | | | | | | | | | |
Loans Payable | Loan Agreement, April 15, 2020, Collateralized Borrowings In US Dollars | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt instrument, face amount | ¥ | | | | | | | | | | | | | | | | | | | | | | | | | ¥ 80,000,000 | | | | | | | | | | | |
Loans Payable | Loan Agreement, April 15, 2020, Tranche One | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from short-term debt | | | | | | | | | | | | | | | | | | | | ¥ 20,000,000 | $ 2,800,000 | | | | | | | | | | | | | | | |
Short-term debt, fixed interest rate | Rate | | | | | | | | | | | | | | | | | | | | | 5.1375% | | | | | | | | | | | | | | | |
Loans Payable | Loan Agreement, April 15, 2020, Tranche Two | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from short-term debt | | | | | | | | | | | | | | | | | | | | | $ 7,100,000 | | | | | | | | | | | | | | | |
Short-term debt, fixed interest rate | Rate | | | | | | | | | | | | | | | | | | | | | 2.70% | | | | | | | | | | | | | | | |
Loans Payable | Loan Agreement, April 15, 2020, Tranche Three | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from short-term debt | | | | | | | | | | | | | | | | | | | | | $ 1,900,000 | | | | | | | | | | | | | | | |
Short-term debt, fixed interest rate | Rate | | | | | | | | | | | | | | | | | | | | | 2.80% | | | | | | | | | | | | | | | |
Loans Payable | Loan Agreement, April 15, 2020, Tranches Two And Three | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Repayments of short-term debt | | | | | | | | | | | | | | | | | | | 9,000,000 | | | | | | | | | | | | | | | | | |
Loans Payable | Loan Agreement, April 15, 2020, Tranche Four | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Proceeds from short-term debt | | | | | | | | | | | | | | | | | | | $ 11,300,000 | | | | | | | | | | | | | | | | | |
Short-term debt, fixed interest rate | Rate | 2.70% | | | | | | | | | | | | | | | | | | | | | | 2.70% | | | | | | | | | | | | | |