Name:	gd_CompensationAndRetirementDisclosureLineItems
Namespace Prefix:	gd_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Expected Contribution Plan To Defined Benefit Contribution Plans

+ References

No definition available.

+ Details

Name:	gd_ExpectedContributionPlanToDefinedBenefitContributionPlans
Namespace Prefix:	gd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number Of Defined Benefit Pension Plans

+ References

No definition available.

+ Details

Name:	gd_NumberOfDefinedBenefitPensionPlans
Namespace Prefix:	gd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage Of Defined Contribution Plans Held From Outstanding Shares

+ References

No definition available.

+ Details

Name:	gd_PercentageOfDefinedContributionPlansHeldFromOutstandingShares
Namespace Prefix:	gd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of pension plan assets held in a single trust for primary domestic government and commercial pension plans

+ References

No definition available.

+ Details

Name:	gd_PercentageOfPensionPlanAssetsHeldInSingleTrustForPrimaryDomesticGovernmentAndCommercialPensionPlans
Namespace Prefix:	gd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period in which the difference between the actual and expected return on plan assets for qualified plans are recognized in years

+ References

No definition available.

+ Details

Name:	gd_PeriodInWhichDifferenceBetweenActualAndExpectedReturnOnPlanAssetsForQualifiedPlansAreRecognizedInYears
Namespace Prefix:	gd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Voluntary Contribution To Pension Plan

+ References

No definition available.

+ Details

Name:	gd_VoluntaryContributionToPensionPlan
Namespace Prefix:	gd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of common stock held in a trust that has been set up specifically to accumulate stock for the sole purpose of distribution to participating employees but not yet earned.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 93-6

-Paragraph 14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 40

-Section 25

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=6418455&loc=d3e16701-113920

+ Details

Name:	us-gaap_CommonStockSharesHeldInEmployeeTrustShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Accumulated Benefit Obligation

-URI http://asc.fasb.org/extlink&oid=6503844

+ Details

Name:	us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph m

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (m)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The effect of a one-percentage- point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph m

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (m)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

+ Details

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

- Definition

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph m

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (m)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph m

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (m)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

+ Details

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

- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 11

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

+ Details

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

Retirement Plans (Narrative) (Details) (USD $) Share data in Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Compensation And Retirement Disclosure Line Items
Defined contribution plan, cost recognized	$ 203,000,000	$ 198,000,000	$ 195,000,000
Voluntary contribution to pension plan	300,000,000
Common stock, shares held in employee trust, shares	33	36
Percentage of defined contribution plans held from outstanding shares	10.00%	10.00%
Defined benefit plan, accumulated benefit obligation	9,800,000,000	8,900,000,000
Defined benefit plan, effect of one percentage point increase on accumulated post-retirement benefit obligation	94,000,000
Defined benefit plan, effect of one percentage point decrease on accumulated post-retirement benefit obligation	78,000,000
Defined benefit plan, effect of one percentage point increase on service and interest cost components	7,000,000
Defined benefit plan, effect of one percentage point decrease on service and interest cost components	6,000,000
Percentage of pension plan assets held in a single trust for primary domestic government and commercial pension plans	90.00%
Period in which the difference between the actual and expected return on plan assets for qualified plans are recognized in years	5
Pension Benefits [Member]
Compensation And Retirement Disclosure Line Items
Defined contribution plan, cost recognized	351,000,000
Expected contribution to defined benefit contribution plans	500,000,000
Other Post-Retirement Benefits [Member]
Compensation And Retirement Disclosure Line Items
Defined contribution plan, cost recognized	31,000,000
Expected contribution to defined benefit contribution plans	$ 27,000,000
Noncontributory [Member] \| Government Business Employees [Member] \| Pension Benefits [Member]
Compensation And Retirement Disclosure Line Items
Number of defined benefit pension plans	6
Noncontributory [Member] \| Commercial Business Employees [Member] \| Pension Benefits [Member]
Compensation And Retirement Disclosure Line Items
Number of defined benefit pension plans	2
Contributory [Member] \| Government Business Employees [Member] \| Pension Benefits [Member]
Compensation And Retirement Disclosure Line Items
Number of defined benefit pension plans	6
Contributory [Member] \| Commercial Business Employees [Member] \| Pension Benefits [Member]
Compensation And Retirement Disclosure Line Items
Number of defined benefit pension plans	4