Name:	fhlba_LoansAndLeasesReceivableUnamortizedDiscounts
Namespace Prefix:	fhlba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Reflects the cumulative amount of premiums over the face amount of loans that are being amortized into income as an adjustment to yield.

No definition available.

Name:	fhlba_LoansAndLeasesReceivableUnamortizedPremiums
Namespace Prefix:	fhlba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Reflects the aggregate unpaid principal balance of all categories of loans and leases held in portfolio.

No definition available.

Name:	fhlba_LoansAndLeasesReceivableUnpaidPrincipalBalance
Namespace Prefix:	fhlba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount before allowance of consumer mortgage. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes subordinated loans such as home equity lines of credit and loans and leases covered under loss sharing agreements

No definition available.

Name:	fhlba_LoansandLeasesReceivableGrossConsumerMortgage
Namespace Prefix:	fhlba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Mortgage Loans on Real Estate, Original Contractual Terms

No definition available.

Name:	fhlba_MortgageLoansOnRealEstateOriginalContractualTerms
Namespace Prefix:	fhlba_
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_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=fhlba_LoansReceivableWithFixedRatesOfInterestMediumTermMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=fhlba_LoansReceivableWithFixedRatesOfInterestLongTermMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_ConventionalLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: