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Cash flows from operating activities.

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Amount of borrowings classified as other, maturing within one year or the normal operating cycle, if longer.

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Uncertain income tax percentage.

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Amount of working capital deficit.

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Description of risks that arise due to the volume of business transacted with a particular customer. At a minimum, the description informs financial statement users of the general nature of the risk, but excludes "Information about Major Customers" that may be disclosed elsewhere (for instance, segment disclosures).

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates, classified as other. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of revenue and income classified as other.

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Significant Accounting Policies (Details) ¥ / shares in Units, ¥ in Thousands, $ in Thousands	12 Months Ended				14 Months Ended
	Dec. 31, 2020 CNY (¥) ¥ / shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 CNY (¥)	Dec. 31, 2018 CNY (¥)	Feb. 28, 2021 CNY (¥)	Feb. 28, 2021 USD ($)	Mar. 31, 2021 CNY (¥)	Dec. 31, 2020 USD ($)	Nov. 30, 2020 CNY (¥)	Apr. 30, 2019
Significant Accounting Policies (Details) [Line Items]
Working capital deficit	¥ 371,553
Accumulated deficit	(2,240,205)		¥ (1,750,475)					$ (343,326)
Loss from operations	(494,700)		(705,700)	¥ (456,900)
Cash flows from operating activities	(17,337)		(223,357)	52,071
Line of credit	90,000
Impairment loss on right of use assets	4,667		21,103	94,311
Impairment loss on property plant equipment	3,460		9,479	16,892
Impairment loss property held for sale	¥ 36,505	$ 5,595	52,030	111,203
Buying rate per share (in Yuan Renminbi per share) \| ¥ / shares	¥ 6,525
Voting percentage										100.00%
Other income	¥ 13,931		16,782	31,783
Uncertain income tax percentage	50.00%	50.00%
Cash and cash equivalents	¥ 123,385		171,915
Short term borrowings	¥ 1,000		28,788
Concentration risk, description	There are two customers individually represent greater than 10% of total net revenue for the year ended December 31, 2019, while there is no customer individually represent greater than 10% of total net revenue for the year ended December 31, 2020. There is one customer individually represent greater than 10% of total accounts receivable as of December 31, 2019, while there are three customers individually represent greater than 10% of total accounts receivable as of December 31, 2020.There are no suppliers that individually represent greater than 10% of the total cost of revenue (excluding impairment loss) for the years ended December 31, 2019 and 2020.	There are two customers individually represent greater than 10% of total net revenue for the year ended December 31, 2019, while there is no customer individually represent greater than 10% of total net revenue for the year ended December 31, 2020. There is one customer individually represent greater than 10% of total accounts receivable as of December 31, 2019, while there are three customers individually represent greater than 10% of total accounts receivable as of December 31, 2020.There are no suppliers that individually represent greater than 10% of the total cost of revenue (excluding impairment loss) for the years ended December 31, 2019 and 2020.
PRC Commercial Bank [Member]
Significant Accounting Policies (Details) [Line Items]
Line of credit									¥ 90,000
Term deposit to the commercial bank	¥ 4,760
PRC Commercial Bank One [Member]
Significant Accounting Policies (Details) [Line Items]
Term deposit to the commercial bank	¥ 6,750
Subsequent Event [Member]
Significant Accounting Policies (Details) [Line Items]
Financing proceeds through ipo					¥ 120,791	$ 18,512
Subsequent Event [Member] \| Unused lines of Credit [Member]
Significant Accounting Policies (Details) [Line Items]
Line of credit							¥ 20,000
Minimum [Member]
Significant Accounting Policies (Details) [Line Items]
Voting percentage	20.00%							20.00%
Maximum [Member]
Significant Accounting Policies (Details) [Line Items]
Voting percentage	50.00%							50.00%
Notes Payable [Member]
Significant Accounting Policies (Details) [Line Items]
Notes payable	¥ 29,159
Right of Use Assets [Member]
Significant Accounting Policies (Details) [Line Items]
Impairment loss property held for sale	¥ 28,378		¥ 21,448