| **Changes in Estimate (Details) - USD ($) $ / shares in Units, $ in Millions** | 3 Months Ended |
|--------------------------------------------------------------------------------|----------------|
||
| **Change in Accounting Estimate [Line Items]**                                 |           |   |
| Operating income                                                               | $ 272          | $ 246 |
| Contracts Accounted for under Percentage of Completion                         |           |   |
| **Change in Accounting Estimate [Line Items]**                                 |           |   |
| Operating income                                                               | 11             | 13 |
| Operating income, net of tax                                                   | $ 6            | $ 8 |
| Operating income per diluted share (in dollars per share)                      | $ 0.05         | $ 0.06 |

| X                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Operating Income (Loss), Net of Tax
+ References
No definition available.
+ Details**Name:**hrs_OperatingIncomeLossNetofTax**Namespace Prefix:**hrs_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Operating Income (Loss), Per Diluted Share
+ References
No definition available.
+ Details**Name:**hrs_OperatingIncomeLossPerDilutedShare**Namespace Prefix:**hrs_**Data Type:**num:perShareItemType**Balance Type:**na**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_ChangeInAccountingEstimateLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net result for the period of deducting operating expenses from operating revenues.
+ References
No definition available.
+ Details**Name:**us-gaap_OperatingIncomeLoss**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_ChangeInAccountingEstimateByTypeAxis=us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |