| **Business Combinations - Intangible Assets Acquired (Details) - Exelis - USD ($) $ in Millions** | 12 Months Ended |         |         |
|---------------------------------------------------------------------------------------------------|-----------------|---------|---------|
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| **Identifiable intangible assets**                                                                |            |    |    |
| Weighted average amortization period (in years)                                                   | 13 years        |    |    |
| Identifiable intangible assets                                                                    | $ 1,618         | $ 1,618 | $ 1,606 |
| Customer Relationships                                                                            |            |    |    |
| **Identifiable intangible assets**                                                                |            |    |    |
| Weighted average amortization period (in years)                                                   | 13 years        |    |    |
| Identifiable intangible assets                                                                    | $ 1,413         |    |    |
| Developed Technology                                                                              |            |    |    |
| **Identifiable intangible assets**                                                                |            |    |    |
| Weighted average amortization period (in years)                                                   | 11 years        |    |    |
| Identifiable intangible assets                                                                    | $ 150           |    |    |
| Trade names and trademarks - Exelis                                                               |            |    |    |
| **Identifiable intangible assets**                                                                |            |    |    |
| Weighted average amortization period (in years)                                                   | 2 years         |    |    |
| Identifiable intangible assets                                                                    | $ 15            |    |    |
| Trade names and trademarks - Product                                                              |            |    |    |
| **Identifiable intangible assets**                                                                |            |    |    |
| Weighted average amortization period (in years)                                                   | 10 years        |    |    |
| Identifiable intangible assets                                                                    | $ 40            |    |    |

| X                                                                                                                                                                                                                                                            |
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| - Definition
Identifiable Intangible Assets Abstract.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
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| - Definition
Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of intangible assets, excluding goodwill, acquired at the acquisition date.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472
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| X                                                                                                                                                                                    |
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