Segment Financial Information - Capital Expenditures, Depreciation and Amortization and Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 04, 2026	Mar. 29, 2025	Jan. 03, 2026
Other Information by Segment
Capital Expenditures	$ 133	$ 56
Depreciation and Amortization	96	92
Assets	18,141		$ 18,129
Manufacturing group
Other Information by Segment
Capital Expenditures	133	56
Depreciation and Amortization	96	92
Assets	17,457		17,452
Manufacturing group \| Corporate
Other Information by Segment
Capital Expenditures	2	0
Depreciation and Amortization	2	2
Assets	4,264		4,688
Manufacturing group \| Textron Aviation \| Operating Segment
Other Information by Segment
Capital Expenditures	32	26
Depreciation and Amortization	41	39
Assets	5,144		5,103
Manufacturing group \| Bell \| Operating Segment
Other Information by Segment
Capital Expenditures	72	15
Depreciation and Amortization	24	22
Assets	3,410		3,132
Manufacturing group \| Textron Systems \| Operating Segment
Other Information by Segment
Capital Expenditures	6	5
Depreciation and Amortization	12	12
Assets	2,233		2,224
Manufacturing group \| Industrial \| Operating Segment
Other Information by Segment
Capital Expenditures	21	10
Depreciation and Amortization	17	17
Assets	2,406		2,305
Finance group
Other Information by Segment
Capital Expenditures	0	0
Depreciation and Amortization	0	$ 0
Assets	684		677
Finance group \| Finance \| Operating Segment
Other Information by Segment
Assets	$ 684		$ 677