Name:	athm_PercentageOfGeneralReserveFundOfRegisteredCapital
Namespace Prefix:	athm_
Data Type:	num:percentItemType
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Period Type:	duration

Represents the minimum percentage of after-tax profit transferred by Chinese subsidiaries to general reserve fund.

No definition available.

Name:	athm_PercentageOfProfitAfterTaxForAppropriationToGeneralReserve
Namespace Prefix:	athm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Restricted Net Assets [Abstract]

No definition available.

Name:	athm_RestrictedNetAssetsAbstract
Namespace Prefix:	athm_
Data Type:	xbrli:stringItemType
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Period Type:	duration

Amount of restricted net assets of consolidated and unconsolidated subsidiaries as of the end of the most recently completed fiscal year.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e)(3)(ii))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

A segregation of retained earnings which is unavailable for dividend distribution. Includes also retained earnings appropriated for loss contingencies.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(23)(a)(4)(i))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-03(30)(a)(3)(ii))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=65888546&loc=d3e21346-112643

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=65888546&loc=d3e21332-112643