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Acquisitions and Divestitures, Goodwill and Intangible Assets - Additional Information (Details) $ / shares in Units, $ in Millions |  | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Apr. 03, 2018 USD ($) $ / shares | Jun. 30, 2019 USD ($) | Jul. 01, 2018 USD ($) | Jun. 30, 2019 USD ($) business | Jul. 01, 2018 USD ($) | Dec. 31, 2018 USD ($) business
Business Acquisition [Line Items] |  |  |  |  |  |
Amortization expense of intangibles | $ |  | $ 70 | $ 84 | $ 140 | $ 104 |
CSRA |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Payments to acquire businesses, gross | $ | $ 9,700 |  |  |  |  |
Series of Individually Immaterial Business Acquisitions |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Payments to acquire businesses, gross | $ |  |  |  | $ 17 |  | $ 400
Number of businesses acquired |  |  |  |  |  | 5
Series of Individually Immaterial Business Acquisitions | Aerospace |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Number of businesses acquired |  |  |  | 1 |  | 2
Series of Individually Immaterial Business Acquisitions | Mission Systems |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Number of businesses acquired |  |  |  | 1 |  |
Series of Individually Immaterial Business Acquisitions | Information Technology |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Number of businesses sold |  |  |  | 1 |  | 2
Common Stock | CSRA |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Percentage of interest acquired | 100.00% |  |  |  |  |
Cash acquisition price (in dollars per share) | $ / shares | $ 41.25 |  |  |  |  |

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- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274 + Details
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