| **Business Segment Information - Total Assets by Segment (Details) - USD ($) $ in Millions** | Apr. 03, 2020 | Jan. 03, 2020 |
|----------------------------------------------------------------------------------------------|---------------|---------------|
| **Segment Reporting Information [Line Items]**                                               |          |          |
| Assets                                                                                       | $ 38,105      | $ 38,336      |
| Identifiable intangibles assets acquired                                                     | 8,171         | 8,458         |
| Corporate                                                                                    |          |          |
| **Segment Reporting Information [Line Items]**                                               |          |          |
| Assets                                                                                       | 9,807         | 10,112        |
| Corporate | Exelis                                                                           |          |          |
| **Segment Reporting Information [Line Items]**                                               |          |          |
| Identifiable intangibles assets acquired                                                     | 8,200         | 8,500         |
| Integrated Mission Systems                                                                   |          |          |
| **Segment Reporting Information [Line Items]**                                               |          |          |
| Assets                                                                                       | 7,999         | 7,896         |
| Space and Airborne Systems                                                                   |          |          |
| **Segment Reporting Information [Line Items]**                                               |          |          |
| Assets                                                                                       | 6,948         | 6,829         |
| Communication Systems                                                                        |          |          |
| **Segment Reporting Information [Line Items]**                                               |          |          |
| Assets                                                                                       | 5,928         | 5,930         |
| Aviation Systems                                                                             |          |          |
| **Segment Reporting Information [Line Items]**                                               |          |          |
| Assets                                                                                       | $ 7,423       | $ 7,569       |

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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.
+ References
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| - 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.
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