Accrued Liabilities and Other Payables - Schedule of accrued liabilities and other payable (Detail) ¥ in Thousands, $ in Thousands	Sep. 30, 2020 CNY (¥)	Sep. 30, 2020 USD ($)	Dec. 31, 2019 CNY (¥)
Payables and Accruals [Abstract]
Accrued marketing expenses	¥ 260,210		¥ 43,765
Accrued liabilities for learning services and online marketing services	119,591		85,598
Accrued outside labor service fee	59,082		10,488
Accrued administrative expenses	26,014		7,846
Accrued technical expenses	23,843		8,960
Deferred government grant	23,342
Operating lease liabilities-current portion	19,457		4,166
Warehousing and logistics fees	10,498		3,469
Accrued professional fee	10,474		18,334
Payables for property and equipment	6,614
Deposits payable to service providers	1,981		2,542
Others	22,391		7,475
Total	¥ 583,497	$ 85,940	¥ 192,643

Accrued administrative services.

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- Definition

Accrued liabilities for learning services and online marketing services.

+ References

No definition available.

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- Definition

Accrued outside labour service fee.

+ References

No definition available.

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- Definition

Accrued technical expenses.

+ References

No definition available.

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- Definition

Deferred government grant.

+ References

No definition available.

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- Definition

Payable for property plant and equipment.

+ References

No definition available.

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- Definition

Warehousing and logistics fees payable.

+ References

No definition available.

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- Definition

Amount of expenses incurred but not yet paid nor invoiced, and liabilities classified as other.

+ References

No definition available.

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for the marketing, trade and selling of the entity's goods and services. Marketing costs would include expenditures for planning and executing the conception, pricing, promotion, and distribution of ideas, goods, and services; costs of public relations and corporate promotions; and obligations incurred and payable for sales discounts, rebates, price protection programs, etc. offered to customers and under government programs. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

No definition available.

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 210
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- Definition

Amount of liability for consideration received or receivable from customer which is not included in transaction price, when consideration is expected to be refunded to customer, classified as current.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 55
-Paragraph 27
-URI http://asc.fasb.org/extlink&oid=121551570&loc=SL49130611-203046-203046

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- Definition

Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
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Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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