Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 04, 2026	Mar. 29, 2025
Disaggregation of Revenue [Line Items]
Revenues	$ 3,695	$ 3,306
United States
Disaggregation of Revenue [Line Items]
Revenues	2,647	2,278
Europe
Disaggregation of Revenue [Line Items]
Revenues	384	321
Other international
Disaggregation of Revenue [Line Items]
Revenues	664	707
Commercial
Disaggregation of Revenue [Line Items]
Revenues	2,540	2,382
U.S. Government
Disaggregation of Revenue [Line Items]
Revenues	1,155	924
Textron Aviation
Disaggregation of Revenue [Line Items]
Revenues	1,485	1,216
Textron Aviation \| United States
Disaggregation of Revenue [Line Items]
Revenues	1,100	912
Textron Aviation \| Europe
Disaggregation of Revenue [Line Items]
Revenues	150	89
Textron Aviation \| Other international
Disaggregation of Revenue [Line Items]
Revenues	235	215
Textron Aviation \| Commercial
Disaggregation of Revenue [Line Items]
Revenues	1,391	1,147
Textron Aviation \| U.S. Government
Disaggregation of Revenue [Line Items]
Revenues	94	69
Textron Aviation \| Aircraft
Disaggregation of Revenue [Line Items]
Revenues	954	733
Textron Aviation \| Aftermarket parts and services
Disaggregation of Revenue [Line Items]
Revenues	531	483
Bell
Disaggregation of Revenue [Line Items]
Revenues	1,070	983
Bell \| United States
Disaggregation of Revenue [Line Items]
Revenues	867	682
Bell \| Europe
Disaggregation of Revenue [Line Items]
Revenues	26	56
Bell \| Other international
Disaggregation of Revenue [Line Items]
Revenues	177	245
Bell \| Commercial
Disaggregation of Revenue [Line Items]
Revenues	275	361
Bell \| U.S. Government
Disaggregation of Revenue [Line Items]
Revenues	795	622
Bell \| Military aircraft and support programs
Disaggregation of Revenue [Line Items]
Revenues	795	634
Bell \| Commercial helicopters, parts and services
Disaggregation of Revenue [Line Items]
Revenues	275	349
Textron Systems
Disaggregation of Revenue [Line Items]
Revenues	338	299
Textron Systems \| United States
Disaggregation of Revenue [Line Items]
Revenues	306	272
Textron Systems \| Europe
Disaggregation of Revenue [Line Items]
Revenues	14	12
Textron Systems \| Other international
Disaggregation of Revenue [Line Items]
Revenues	18	15
Textron Systems \| Commercial
Disaggregation of Revenue [Line Items]
Revenues	77	73
Textron Systems \| U.S. Government
Disaggregation of Revenue [Line Items]
Revenues	261	226
Industrial
Disaggregation of Revenue [Line Items]
Revenues	786	792
Industrial \| United States
Disaggregation of Revenue [Line Items]
Revenues	370	408
Industrial \| Europe
Disaggregation of Revenue [Line Items]
Revenues	192	164
Industrial \| Other international
Disaggregation of Revenue [Line Items]
Revenues	224	220
Industrial \| Commercial
Disaggregation of Revenue [Line Items]
Revenues	781	785
Industrial \| U.S. Government
Disaggregation of Revenue [Line Items]
Revenues	5	7
Industrial \| Fuel systems and functional components
Disaggregation of Revenue [Line Items]
Revenues	486	450
Industrial \| Specialized vehicles
Disaggregation of Revenue [Line Items]
Revenues	300	342
Finance
Disaggregation of Revenue [Line Items]
Revenues	16	16
Finance \| United States
Disaggregation of Revenue [Line Items]
Revenues	4	4
Finance \| Europe
Disaggregation of Revenue [Line Items]
Revenues	2	0
Finance \| Other international
Disaggregation of Revenue [Line Items]
Revenues	10	12
Finance \| Commercial
Disaggregation of Revenue [Line Items]
Revenues	16	16
Finance \| U.S. Government
Disaggregation of Revenue [Line Items]
Revenues	$ 0	$ 0