Bank Borrowing (Details)												1 Months Ended							3 Months Ended
	Sep. 30, 2020 CNY (¥) Rate	Sep. 30, 2020 USD ($)	Jun. 28, 2020	Jun. 24, 2020	Apr. 26, 2020 CNY (¥)	Sep. 23, 2019 CNY (¥)	Aug. 09, 2019 USD ($)	Mar. 12, 2019 CNY (¥)	May 09, 2018 CNY (¥)	May 01, 2018 USD ($)	Aug. 15, 2017 USD ($)	Apr. 30, 2020 CNY (¥)	Apr. 30, 2020 USD ($)	Dec. 31, 2019 CNY (¥)	Oct. 31, 2019 CNY (¥)	Mar. 31, 2019 CNY (¥)	Jul. 31, 2018 USD ($)	Jan. 31, 2018 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 CNY (¥)	Jun. 30, 2020 USD ($) Rate	Dec. 31, 2019 CNY (¥)	Sep. 30, 2020 USD ($) Rate	Apr. 26, 2020 USD ($)	Apr. 15, 2020 CNY (¥)	Apr. 15, 2020 USD ($)	Dec. 31, 2019 USD ($)	Oct. 31, 2019 USD ($)	Sep. 23, 2019 USD ($)	Mar. 12, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 04, 2018 CNY (¥)	Nov. 29, 2018 CNY (¥)	Nov. 16, 2018 CNY (¥)	Nov. 16, 2018 USD ($)	May 09, 2018 USD ($)
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															¥ 60,000,000.0													$ 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							$ 30,000,000.0
Accounts receivable factoring agreement, remaining borrowing capacity																							30,000,000.0
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									¥ 400,000,000.0																											$ 62,800,000
Debt instrument, term									5 years
Nominal sale amount at end of lease term | ¥									¥ 1
Amount outstanding	¥ 271,000,000.0																						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																											$ 24,000,000.0
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	¥ 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 | ¥																						¥ 6,000,000.0
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%				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											$ 30,000,000.0
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						¥ 50,000,000.0																							$ 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																																		¥ 72,000,000.0	$ 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																			9,000,000.0
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%