Pension Plans - Schedule of Allocation of Plan Assets (Details) - UNITED STATES - USD ($) $ in Millions	Sep. 26, 2026	Dec. 31, 2025
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 9,015	$ 0
Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	6,251
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	744
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	4,731
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	776
Honeywell Aerospace common stock \| Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	741
Honeywell Aerospace common stock \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	741
Honeywell Aerospace common stock \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Honeywell Aerospace common stock \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Short term investments \| Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	338
Short term investments \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3
Short term investments \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	335
Short term investments \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Government securities \| Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,521
Government securities \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Government securities \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,521
Government securities \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Corporate bonds \| Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,867
Corporate bonds \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Corporate bonds \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,867
Corporate bonds \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Mortgage/Asset-backed securities \| Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	8
Mortgage/Asset-backed securities \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Mortgage/Asset-backed securities \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	8
Mortgage/Asset-backed securities \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Direct private investments \| Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	294
Direct private investments \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Direct private investments \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Direct private investments \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	294
Real estate properties \| Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	482
Real estate properties \| Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Real estate properties \| Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Real estate properties \| Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	482
Private equity funds \| Investments measured at NAV:
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	961
Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	7,212
Other items to reconcile to fair value of plan assets
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 1,803