Employee Benefit Plans - Benefit Plan Assets Measured at Fair Value on Recurring Basis(Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Equities and equity-related instruments \| Common Stock
Defined Benefit Plan, Funded Status of Plan
Employer contributions	$ 350	$ 350
Fair Value, Measurements, Recurring
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	15,322	10,811
Investments measured at net asset value (NAV)	7,378	5,724
Benefit plan assets	7,944	5,087
Fair Value, Measurements, Recurring \| Equities and equity-related instruments
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	2,046	2,035
Investments measured at net asset value (NAV)	1,375	1,214
Fair Value, Measurements, Recurring \| Equities and equity-related instruments \| Common Stock
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	801	386
Fair Value, Measurements, Recurring \| Cash equivalents
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	1,432	1,468
Fair Value, Measurements, Recurring \| Fixed income and fixed income-related instruments
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	3,665	1,198
Investments measured at net asset value (NAV)	311	270
Fair Value, Measurements, Recurring \| Level 1
Defined Benefit Plan, Funded Status of Plan
Benefit plan assets	3,586	2,643
Fair Value, Measurements, Recurring \| Level 1 \| Equities and equity-related instruments
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	2,033	2,021
Fair Value, Measurements, Recurring \| Level 1 \| Equities and equity-related instruments \| Common Stock
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	801	386
Fair Value, Measurements, Recurring \| Level 1 \| Cash equivalents
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	735	228
Fair Value, Measurements, Recurring \| Level 1 \| Fixed income and fixed income-related instruments
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	17	8
Fair Value, Measurements, Recurring \| Level 2
Defined Benefit Plan, Funded Status of Plan
Benefit plan assets	4,358	2,444
Fair Value, Measurements, Recurring \| Level 2 \| Equities and equity-related instruments
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	13	14
Fair Value, Measurements, Recurring \| Level 2 \| Equities and equity-related instruments \| Common Stock
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring \| Level 2 \| Cash equivalents
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	697	1,240
Fair Value, Measurements, Recurring \| Level 2 \| Fixed income and fixed income-related instruments
Defined Benefit Plan, Funded Status of Plan
Fair value of plan assets	$ 3,648	$ 1,190

Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets

No definition available.

Name:	dal_DefinedBenefitPlanAlternativeInvestmentsFairValueOfPlanAssets
Namespace Prefix:	dal_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value Investments

+ References

No definition available.

+ Details

Name:	dal_DefinedBenefitPlanFairValueofPlanAssetsExcludingNetAssetValueInvestments
Namespace Prefix:	dal_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of contribution received by defined benefit plan from employer which increases plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)(ii)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2709-114920

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)(iv)(01)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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

- Definition

Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: