XML 94 R85.htm IDEA: XBRL DOCUMENT v2.4.1.9
Netting Arrangements (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Assets    
Derivative assets, gross amount $ 7,291us-gaap_DerivativeFairValueOfDerivativeAsset $ 6,643us-gaap_DerivativeFairValueOfDerivativeAsset
Derivative assets, gross amount offset (5,626)us-gaap_DerivativeAssetFairValueGrossLiability (5,186)us-gaap_DerivativeAssetFairValueGrossLiability
Derivative assets, net amount presented in the condensed consolidated balance sheets 1,665us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral 1,457us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments (227)us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction (116)us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral (3)us-gaap_DerivativeCollateralObligationToReturnSecurities (40)us-gaap_DerivativeCollateralObligationToReturnSecurities
Derivative assets, net amount 1,435us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral 1,301us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral
Securities purchased under agreements to resell or similar arrangements, gross amount 39,180us-gaap_SecuritiesPurchasedUnderAgreementsToResellGross 47,550us-gaap_SecuritiesPurchasedUnderAgreementsToResellGross
Securities purchased under agreements to resell or similar arrangements, gross amount offset 0us-gaap_SecuritiesPurchasedUnderAgreementsToResellLiability 0us-gaap_SecuritiesPurchasedUnderAgreementsToResellLiability
Securities purchased under agreements to resell or similar arrangements, net amount presented in the condensed consolidated balance sheets 39,180fnm_SecuritiesPurchasedUnderAgreementsToResellAmountNotOffsetAgainstCollateral 47,550fnm_SecuritiesPurchasedUnderAgreementsToResellAmountNotOffsetAgainstCollateral
Securities purchased under agreements to resell, under master netting arrangement, amounts not offset in the condensed consolidated balance sheets, financial instruments 0us-gaap_SecuritiesPurchasedUnderAgreementsToResellNotOffsetPolicyElectionDeduction 0us-gaap_SecuritiesPurchasedUnderAgreementsToResellNotOffsetPolicyElectionDeduction
Securities purchased under agreements to resell or similar arrangements, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral (39,180)us-gaap_SecuritiesPurchasedUnderAgreementsToResellCollateralObligationToReturnSecurities (47,550)us-gaap_SecuritiesPurchasedUnderAgreementsToResellCollateralObligationToReturnSecurities
Securities purchased under agreements to resell or similar arrangements, net amount 0fnm_SecuritiesPurchasedUnderAgreementsToResellSubjectToMasterNettingArrangementsAmountOffsetAgainstCollateral 0fnm_SecuritiesPurchasedUnderAgreementsToResellSubjectToMasterNettingArrangementsAmountOffsetAgainstCollateral
Total assets, gross amount 46,471us-gaap_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedGross 54,193us-gaap_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedGross
Total assets, gross amount offset (5,626)us-gaap_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedLiability (5,186)us-gaap_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedLiability
Total assets, net amount presented in the condensed consolidated balance sheets 40,845fnm_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedSubjectToMasterNettingArrangement 49,007fnm_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedSubjectToMasterNettingArrangement
Total assets, under master netting arrangements, not offset in the condensed consolidated balance sheets, financial instruments (227)fnm_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSubjectToMasterNettingArrangementNotOffsetFinancialInstruments (116)fnm_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSubjectToMasterNettingArrangementNotOffsetFinancialInstruments
Total assets, under master netting arrangements, not offset in the condensed consolidated balance sheets, collateral (39,183)us-gaap_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedCollateralObligationToReturnSecurities (47,590)us-gaap_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellSecuritiesBorrowedCollateralObligationToReturnSecurities
Total assets, net amount 1,435fnm_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellUnderMasterNettingArrangementsAmountOffsetAgainstCollateral 1,301fnm_DerivativeAssetSecuritiesPurchasedUnderAgreementsToResellUnderMasterNettingArrangementsAmountOffsetAgainstCollateral
Liabilities:    
Derivative liabilities, gross amount (12,837)us-gaap_DerivativeFairValueOfDerivativeLiability (10,807)us-gaap_DerivativeFairValueOfDerivativeLiability
Derivative liabilities, gross amount offset 12,036us-gaap_DerivativeLiabilityFairValueGrossAsset 10,194us-gaap_DerivativeLiabilityFairValueGrossAsset
Derivative liabilities, net amount presented in the condensed consolidated balance sheets (801)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral (613)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments 227fnm_DerivativeLiabilitySubjectToMasterNettingArrangementNotOffsetFinancialInstruments 116fnm_DerivativeLiabilitySubjectToMasterNettingArrangementNotOffsetFinancialInstruments
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral 0us-gaap_DerivativeCollateralRightToReclaimSecurities 0us-gaap_DerivativeCollateralRightToReclaimSecurities
Derivative liabilities, net amount (574)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral (497)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral
Securities sold under agreements to repurchase, gross amount (87)us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseGross (50)us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseGross
Securities sold under agreements to repurchase, gross amount offset 0us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseAsset 0us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseAsset
Securities sold under agreements to repurchase, net amount presented in the condensed consolidated balance sheets (87)fnm_SecuritiesSoldUnderAgreementstoRepurchaseAmountNotOffsetAgainstCollateral (50)fnm_SecuritiesSoldUnderAgreementstoRepurchaseAmountNotOffsetAgainstCollateral
Securities sold under agreements to repurchase, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments 0fnm_SecuritiesSoldUnderAgreementstoRepurchaseUnderMasterNettingArrangementNotOffsetFinancialInstruments 0fnm_SecuritiesSoldUnderAgreementstoRepurchaseUnderMasterNettingArrangementNotOffsetFinancialInstruments
Securities sold under agreements to repurchase, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral 87us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities 50us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities
Securities sold under agreements to repurchase, net amount 0fnm_SecuritiesSoldunderAgreementstoRepurchaseSubjecttoMasterNettingArrangementsAmountOffsetAgainstCollateral 0fnm_SecuritiesSoldunderAgreementstoRepurchaseSubjecttoMasterNettingArrangementsAmountOffsetAgainstCollateral
Total liabilities, gross amount (12,924)us-gaap_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedGross (10,857)us-gaap_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedGross
Total liabilities, gross amount offset 12,036us-gaap_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedAsset 10,194us-gaap_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedAsset
Total liabilities, net amount presented in the condensed consolidated balance sheets (888)fnm_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedSubjectToMasterNettingArrangements (663)fnm_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedSubjectToMasterNettingArrangements
Total liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments 227fnm_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSubjectToMasterNettingArrangementNotOffsetFinancialInstruments 116fnm_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSubjectToMasterNettingArrangementNotOffsetFinancialInstruments
Total liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral 87us-gaap_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedCollateralRightToReclaimSecurities 50us-gaap_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedCollateralRightToReclaimSecurities
Total liabilities, net amount (574)us-gaap_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedAmountOffsetAgainstCollateral (497)us-gaap_DerivativeLiabilitySecuritiesSoldUnderAgreementsToResellSecuritiesLoanedAmountOffsetAgainstCollateral
Risk Management Derivatives [Member]    
Assets    
Derivative assets, gross amount offset (5,626)us-gaap_DerivativeAssetFairValueGrossLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
(5,186)us-gaap_DerivativeAssetFairValueGrossLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Liabilities:    
Derivative liabilities, gross amount offset 12,036us-gaap_DerivativeLiabilityFairValueGrossAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
10,194us-gaap_DerivativeLiabilityFairValueGrossAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Risk Management Derivatives [Member] | OTC Risk Management Derivatives [Member]    
Assets    
Derivative assets, gross amount 5,705us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
5,461us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, gross amount offset (5,705)us-gaap_DerivativeAssetFairValueGrossLiability
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
(5,428)us-gaap_DerivativeAssetFairValueGrossLiability
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, net amount presented in the condensed consolidated balance sheets 0us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
33us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments 0us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral 0us-gaap_DerivativeCollateralObligationToReturnSecurities
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
(33)us-gaap_DerivativeCollateralObligationToReturnSecurities
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, net amount 0us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Liabilities:    
Derivative liabilities, gross amount (8,658)us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
(7,836)us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, gross amount offset 8,424us-gaap_DerivativeLiabilityFairValueGrossAsset
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
7,567us-gaap_DerivativeLiabilityFairValueGrossAsset
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, net amount presented in the condensed consolidated balance sheets (234)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
(269)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments 0fnm_DerivativeLiabilitySubjectToMasterNettingArrangementNotOffsetFinancialInstruments
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0fnm_DerivativeLiabilitySubjectToMasterNettingArrangementNotOffsetFinancialInstruments
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral 0us-gaap_DerivativeCollateralRightToReclaimSecurities
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0us-gaap_DerivativeCollateralRightToReclaimSecurities
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, net amount (234)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
(269)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Risk Management Derivatives [Member] | Cleared Risk Management Derivatives [Member]    
Assets    
Derivative assets, gross amount 1,174us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
927us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, gross amount offset 79us-gaap_DerivativeAssetFairValueGrossLiability
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
242us-gaap_DerivativeAssetFairValueGrossLiability
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, net amount presented in the condensed consolidated balance sheets 1,253us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
1,169us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments 0us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral 0us-gaap_DerivativeCollateralObligationToReturnSecurities
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0us-gaap_DerivativeCollateralObligationToReturnSecurities
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative assets, net amount 1,253us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
1,169us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Liabilities:    
Derivative liabilities, gross amount (3,612)us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
(2,627)us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, gross amount offset 3,612us-gaap_DerivativeLiabilityFairValueGrossAsset
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
2,627us-gaap_DerivativeLiabilityFairValueGrossAsset
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, net amount presented in the condensed consolidated balance sheets 0us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments 0fnm_DerivativeLiabilitySubjectToMasterNettingArrangementNotOffsetFinancialInstruments
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0fnm_DerivativeLiabilitySubjectToMasterNettingArrangementNotOffsetFinancialInstruments
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral 0us-gaap_DerivativeCollateralRightToReclaimSecurities
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0us-gaap_DerivativeCollateralRightToReclaimSecurities
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Derivative liabilities, net amount 0us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
0us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral
/ us-gaap_DerivativeByNatureAxis
= fnm_OTCClearedRiskManagementDerivativesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Mortgage commitment derivatives [Member]    
Assets    
Derivative assets, gross amount 412us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
255us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative assets, gross amount offset 0us-gaap_DerivativeAssetFairValueGrossLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
0us-gaap_DerivativeAssetFairValueGrossLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative assets, net amount presented in the condensed consolidated balance sheets 412us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
255us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments (227)us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
(116)us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative assets, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral (3)us-gaap_DerivativeCollateralObligationToReturnSecurities
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
(7)us-gaap_DerivativeCollateralObligationToReturnSecurities
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative assets, net amount 182us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
132us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Liabilities:    
Derivative liabilities, gross amount (567)us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
(344)us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative liabilities, gross amount offset 0us-gaap_DerivativeLiabilityFairValueGrossAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
0us-gaap_DerivativeLiabilityFairValueGrossAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative liabilities, net amount presented in the condensed consolidated balance sheets (567)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
(344)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, financial instruments 227fnm_DerivativeLiabilitySubjectToMasterNettingArrangementNotOffsetFinancialInstruments
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
116fnm_DerivativeLiabilitySubjectToMasterNettingArrangementNotOffsetFinancialInstruments
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative liabilities, under master netting arrangements, amounts not offset in the condensed consolidated balance sheets, collateral 0us-gaap_DerivativeCollateralRightToReclaimSecurities
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
0us-gaap_DerivativeCollateralRightToReclaimSecurities
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
Derivative liabilities, net amount $ (340)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember
$ (228)us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral
/ us-gaap_DerivativeInstrumentRiskAxis
= fnm_MortgageCommitmentDerivativesMember