Segment Financial Information - Capital Expenditures, Depreciation and Amortization and Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2025	Sep. 28, 2024	Sep. 27, 2025	Sep. 28, 2024	Dec. 28, 2024
Other Information by Segment
Capital Expenditures	$ 76	$ 71	$ 210	$ 211
Depreciation and Amortization	97	101	289	279
Assets	17,381		17,381		$ 16,838
Manufacturing group
Other Information by Segment
Capital Expenditures			210	211
Depreciation and Amortization			289	279
Assets	16,693		16,693		16,158
Corporate
Other Information by Segment
Capital Expenditures	1	0	1	0
Depreciation and Amortization	2	1	5	5
Assets	3,717		3,717		3,842
Textron Aviation \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	30	30	92	91
Depreciation and Amortization	41	47	118	120
Assets	4,973		4,973		4,624
Bell \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	26	18	59	55
Depreciation and Amortization	23	22	73	61
Assets	3,216		3,216		2,992
Textron Systems \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	7	7	20	22
Depreciation and Amortization	12	12	36	35
Assets	2,088		2,088		2,036
Industrial \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	12	15	37	40
Depreciation and Amortization	17	17	51	52
Assets	2,383		2,383		2,378
Textron eAviation \| Operating Segment \| Manufacturing group
Other Information by Segment
Capital Expenditures	0	1	1	3
Depreciation and Amortization	2	$ 2	6	$ 6
Assets	316		316		286
Finance \| Operating Segment
Other Information by Segment
Assets	$ 688		$ 688		$ 680