Name:	af_ExtendedPriorPeriodOverWhichLossExperienceFactorsAreEvaluatedToConsiderTrends
Namespace Prefix:	af_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the length of period four, over which the historical loss experience is reviewed.

No definition available.

Name:	af_LengthOfPeriodFourOverWhichHistoricalLossExperienceIsAnalyzed
Namespace Prefix:	af_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the length of period one, over which the historical loss experience is reviewed.

No definition available.

Name:	af_LengthOfPeriodOneOverWhichHistoricalLossExperienceIsAnalyzed
Namespace Prefix:	af_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the length of period three, over which the historical loss experience is reviewed.

No definition available.

Name:	af_LengthOfPeriodThreeOverWhichHistoricalLossExperienceIsAnalyzed
Namespace Prefix:	af_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the length of period two, over which the historical loss experience is reviewed.

No definition available.

Name:	af_LengthOfPeriodTwoOverWhichHistoricalLossExperienceIsAnalyzed
Namespace Prefix:	af_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the minimum length of period, over which the historical loss experience is evaluated for a particular loan type for which the entity may not have sufficient loss history to develop a reasonable estimate of loss.

No definition available.

Name:	af_MinimumLengthOfPeriodOverWhichHistoricalLossExperienceIsAnalyzedForParticularLoanTypeThatMayNotHaveSufficientLossHistory
Namespace Prefix:	af_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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.

No definition available.

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

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Reflects the amount of the write-down related to a troubled debt restructuring.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554

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

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL49126937-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

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

- References

No definition available.