Segment Information - Revenue by Segment and Reconciliation of Segment Profit to Income Before Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 03, 2021	Jul. 04, 2020	Jul. 03, 2021	Jul. 04, 2020
Revenues
Total revenues	$ 3,191	$ 2,472	$ 6,070	$ 5,249
Reconciliation of segment profit to income from continuing operations before income taxes
Special charges	(4)	(78)	(10)	(117)
Gain on business disposition	2	0	17	0
Income (loss) from continuing operations before income taxes	218	(118)	408	(49)
Operating Segment
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	289	82	545	238
Reconciling Items
Reconciliation of segment profit to income from continuing operations before income taxes
Corporate expenses and other, net	37	30	(77)	(44)
Special charges	(4)	78	(10)	(117)
Gain on business disposition	2	0	17	0
Inventory charge	0	(55)	0	(55)
Textron Aviation
Revenues
Total revenues	1,161	747	2,026	1,619
Textron Aviation | Operating Segment
Reconciliation of segment profit to income from continuing operations before income taxes
Special charges		(28)		(60)
Bell
Revenues
Total revenues	891	822	1,737	1,645
Textron Systems
Revenues
Total revenues	333	326	661	654
Textron Systems | Operating Segment
Reconciliation of segment profit to income from continuing operations before income taxes
Special charges		(40)		(40)
Industrial
Revenues
Total revenues	794	562	1,619	1,302
Industrial | Operating Segment
Reconciliation of segment profit to income from continuing operations before income taxes
Special charges	(4)	(8)	(10)	(15)
Finance
Revenues
Total revenues	12	15	27	29
Finance | Operating Segment
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	3	4	9	7
Manufacturing group
Reconciliation of segment profit to income from continuing operations before income taxes
Gain on business disposition			17	0
Manufacturing group | Reconciling Items
Reconciliation of segment profit to income from continuing operations before income taxes
Interest expense, net for Manufacturing group	(32)	(37)	(67)	(71)
Manufacturing group | Textron Aviation | Operating Segment
Revenues
Total revenues	1,161	747	2,026	1,619
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	96	(66)	143	(63)
Manufacturing group | Bell | Operating Segment
Revenues
Total revenues	891	822	1,737	1,645
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	110	118	215	233
Manufacturing group | Textron Systems | Operating Segment
Revenues
Total revenues	333	326	661	654
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	48	37	99	63
Manufacturing group | Industrial | Operating Segment
Revenues
Total revenues	794	562	1,619	1,302
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	32	(11)	79	(2)
Finance group
Reconciliation of segment profit to income from continuing operations before income taxes
Gain on business disposition			0	0
Finance group | Finance | Operating Segment
Revenues
Total revenues	$ 12	$ 15	$ 27	$ 29