Stock Options and Other Share-Based Compensation (Details) $ in Millions	3 Months Ended
Apr. 03, 2020 USD ($) plan shares	Mar. 29, 2019 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs related to share-based awards \| $	$ 17	$ 14
SIPs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shareholder approved employee stock incentive plans \| plan	2
L3Harris SIPs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued, net of shares withheld for tax purposes (in shares)	450,183	147,176
L3Harris SIPs \| Restricted Sock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	206,366
L3Harris SIPs \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	583,200
Expected dividend yield	1.55%
Expected volatility	22.74%
Risk free interest rates	0.89%
Expected term	5 years 14 days
L3Harris SIPs \| Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	203,606

Number of shareholder approved employee stock incentive plans.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Net number of share options (or share units) granted during the period.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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