XML 51 R38.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Summary of Significant Accounting Policies (Details) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jul. 01, 2018 USD ($) | Jul. 01, 2018 USD ($) Segment | Jan. 01, 2018 USD ($)
New Accounting Pronouncements |  |  |
Number of operating segments | Segment |  | 5 |
Length of fiscal quarters, weeks |  | 91 days |
Operating Earnings | Accounting Standards Update 2017-07 |  |  |
New Accounting Pronouncements |  |  |
New accounting pronouncement, effect of change in operating results | $ 11 | $ 22 |
Other Income | Accounting Standards Update 2017-07 |  |  |
New Accounting Pronouncements |  |  |
New accounting pronouncement, effect of change in operating results | $ (11) | $ (22) |
Retained Earnings | Accounting Standards Update 2016-01 |  |  |
New Accounting Pronouncements |  |  |
Cumulative effect of new accounting pronouncement in period of adoption |  |  | $ 24
Retained Earnings | Accounting Standards Update 2018-02 |  |  |
New Accounting Pronouncements |  |  |
Cumulative effect of new accounting pronouncement in period of adoption |  |  | 614
Accumulated Other Comprehensive Loss | Accounting Standards Update 2016-01 |  |  |
New Accounting Pronouncements |  |  |
Cumulative effect of new accounting pronouncement in period of adoption |  |  | (24)
Accumulated Other Comprehensive Loss | Accounting Standards Update 2018-02 |  |  |
New Accounting Pronouncements |  |  |
Cumulative effect of new accounting pronouncement in period of adoption |  |  | $ (614)

X
- Definition Length of fiscal quarters, weeks + References No definition available. + Details
Name: | gd_LengthOfFiscalQuartersWeeks
Namespace Prefix: | gd_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cumulative effect of the change in accounting principle or new accounting pronouncement on retained earnings or other components of equity or net assets in the statement of financial position as of the beginning of the earliest period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22580-107794 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22583-107794 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22499-107794 + Details
Name: | us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquityOrNetAssets1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of the effect of a change in accounting principle on operating profit or loss. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22499-107794 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22580-107794 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22583-107794 + Details
Name: | us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfChangeOnOperatingResults
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References No definition available. + Details
Name: | us-gaap_NumberOfOperatingSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OperatingIncomeLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=gd_AccountingStandardsUpdate201707Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OtherIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_RetainedEarningsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201601Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=gd_AccountingStandardsUpdate201802Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedOtherComprehensiveIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |