Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Summary of Significant Accounting Policies (Policies)
Notes Tables
Notes Details

Discontinued Operations - Additional Information (Details)

v3.21.1

Discontinued Operations - Additional Information (Details) $ in Millions			12 Months Ended
	Aug. 24, 2018 CNY (¥)	Aug. 16, 2018 USD ($) entity	Dec. 31, 2018 CNY (¥)
DISCONTINUED OPERATIONS
Special cash dividend \| ¥	¥ 946,600,000		¥ 946,613,862
ATA Online and its direct shareholding companies, ATA Learning and Zhongxiao Zhixing \| Discontinued operation, disposal by sale \| Entities Affiliated With Funds Managed By CDH Investments
DISCONTINUED OPERATIONS
Equity interest transferred (in percent)		17.50%
Equity interest transferred to number of entities \| entity		2
Consideration of disposal		$ 35.0
ATA Online and its direct shareholding companies, ATA Learning and Zhongxiao Zhixing \| Discontinued operation, disposal by sale \| Holding Companies Controlled By Certain Managements
DISCONTINUED OPERATIONS
Equity interest transferred (in percent)		16.50%
Equity interest transferred to number of entities \| entity		3
Consideration of disposal		$ 33.0
ATA Online and its direct shareholding companies, ATA Learning and Zhongxiao Zhixing \| Discontinued operation, disposal by sale \| the LHHY entity
DISCONTINUED OPERATIONS
Equity interest transferred (in percent)		15.00%
Consideration of disposal		$ 30.0
ATA Online and its direct shareholding companies, ATA Learning and Zhongxiao Zhixing \| Discontinued operation, disposal by sale \| New Beauty Holding Limited
DISCONTINUED OPERATIONS
Equity interest transferred (in percent)		51.00%
Consideration of disposal		$ 102.0

- Definition

Percent, ownership interest of a disposal group to which interest is transferred.

+ References

No definition available.

+ Details

Name:	aacg_DisposalGroupPercentageOfOwnershipInterestTransferred
Namespace Prefix:	aacg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Ownership interest transferred to the number of entities.

+ References

No definition available.

+ Details

Name:	aacg_DisposalGroupPercentageOfOwnershipInterestTransferredToNumberOfEntities
Namespace Prefix:	aacg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

+ Details

Name:	us-gaap_DividendsCommonStockCash
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=aacg_AtaOnlineAndItsDirectShareholdingCompaniesAtaLearningAndZhongxiaoZhixingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsDisposedOfBySaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=aacg_EntitiesAffiliatedWithFundsManagedByCDHInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=aacg_HoldingCompaniesControlledByCertainManagementMembersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=aacg_ZhuhaiLihonghuayingEquityInvestmentPartnershipLpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=aacg_NewBeautyHoldingsLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: