Name:	fhlbd_ScheduleofAdvancesClassifiedbyContractualMaturityDateorNextCallDateTableTextBlockLineItems
Namespace Prefix:	fhlbd_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of deposits held by the entity that have been reclassified as loan balances receivable, for example, but not limited to, overdrafts receivable.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-SubTopic 405
-Topic 942
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478353/942-405-50-1

Name:	us-gaap_DepositLiabilitiesReclassifiedAsLoansReceivable1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank) with the earlier of contractual maturity or next call date after the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank) with the earlier of contractual maturity or next call date within the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank) with the earlier of contractual maturity or next call date within the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank) with the earlier of contractual maturity or next call date within the fourth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank) with the earlier of contractual maturity or next call date within the third rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank) with the earlier of contractual maturity or next call date within the second rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank).

No definition available.