Segment Financial Information - Capital Expenditures, Depreciation and Amortization and Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2025	Jun. 29, 2024	Jun. 28, 2025	Jun. 29, 2024	Dec. 28, 2024
Other Information by Segment
Capital Expenditures	$ 78	$ 74	$ 134	$ 140
Depreciation and Amortization	100	90	192	178
Assets	17,076		17,076		$ 16,838
Manufacturing group
Other Information by Segment
Capital Expenditures			134	140
Depreciation and Amortization			192	178
Assets	16,392		16,392		16,158
Corporate
Other Information by Segment
Capital Expenditures	0	0	0	0
Depreciation and Amortization	1	2	3	4
Assets	3,755		3,755		3,842
Textron Aviation \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	37	34	62	61
Depreciation and Amortization	40	37	77	73
Assets	4,823		4,823		4,624
Bell \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	18	18	33	37
Depreciation and Amortization	28	20	50	39
Assets	3,062		3,062		2,992
Textron Systems \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	8	7	13	15
Depreciation and Amortization	12	12	24	23
Assets	2,044		2,044		2,036
Industrial \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	15	14	25	25
Depreciation and Amortization	17	17	34	35
Assets	2,391		2,391		2,378
Textron eAviation \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	0	1	1	2
Depreciation and Amortization	2	$ 2	4	$ 4
Assets	317		317		286
Finance \| Operating Segment
Other Information by Segment
Assets	$ 684		$ 684		$ 680