|**STOCK OPTIONS AND OTHER SHARE-BASED COMPENSATION (Tables)** | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
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|**Share-Based Payment Arrangement [Abstract]**                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
|Summary of Awards Granted, Stock Option and Units             | Awards granted to participants under L3Harris SIPs and the weighted-average grant-date fair value per share during the three quarters ended September 29, 2023 and September 30, 2022 are as follows:Three Quarters Ended September 29, 2023Three Quarters Ended September 30, 2022(In millions, except per share amounts)SharesWeighted-Average Grant-Date Fair ValuePer ShareSharesWeighted-Average Grant-Date Fair ValuePer ShareStock options granted(1)0.4$209.880.4$231.71Restricted stock and restricted stock units granted(2)0.3$200.610.3$224.79Performance share units grants(3)0.2$223.090.2$258.83_______________(1)Other than certain stock options granted in connection with new hires, our stock options generally ratably vest in equal amounts over a three-year period.(2)Other than certain restricted stock units granted in connection with new hires, our restricted stock units generally cliff vest after three-years.(3)Our performance share units are subject to performance criteria and generally vest after the three-year performance period.
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|                                                              | Three Quarters Ended September 29, 2023                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
|(In millions, except per share amounts)                       | Shares                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
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|Stock options granted(1)                                      | 0.4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Restricted stock and restricted stock units granted(2)        | 0.3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Performance share units grants(3)                             | 0.2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

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