Quarterly Data (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended			18 Months Ended
	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016	Dec. 30, 2017
Summary of quarterly data
Total revenues	$ 3,750	$ 3,200	$ 3,726	$ 3,296	$ 4,017	$ 3,484	$ 3,604	$ 3,093	$ 13,972	$ 14,198	$ 13,788
Special charges	(73)				(55)	(25)	(13)	(37)	(73)	(130)	(123)
Gain on business disposition		444							444
Income tax benefit (expense)	(32)	(65)	(36)	(29)	(329)	(44)	(62)	(21)	(162)	(456)	(33)
Income from continuing operations	246	563	224	189	(106)	159	153	100	1,222	306	843
Income from discontinued operations, net of income taxes								1		1	119
Net income	$ 246	$ 563	$ 224	$ 189	$ (106)	$ 159	$ 153	$ 101	$ 1,222	$ 307	$ 962
Basic earnings per share
Continuing operations (in dollars per share)	$ 1.02	$ 2.29	$ 0.88	$ 0.73	$ (0.40)	$ 0.60	$ 0.57	$ 0.37	$ 4.88	$ 1.15	$ 3.11
Discontinued operations (in dollars per share)											0.44
Basic earnings per share (in dollars per share)	$ 1.02	$ 2.29	$ 0.88	$ 0.73	$ (0.40)	$ 0.60	$ 0.57	$ 0.37	$ 4.88	$ 1.15	$ 3.55
Basic average shares outstanding	240,248	246,136	253,904	260,497	263,295	264,624	267,114	270,489	250,196	266,380	270,774
Diluted earnings per share
Continuing operations (in dollars per share)	$ 1.02	$ 2.26	$ 0.87	$ 0.72	$ (0.40)	$ 0.60	$ 0.57	$ 0.37	$ 4.83	$ 1.14	$ 3.09
Discontinued operations (in dollars per share)											0.44
Diluted earnings per share (in dollars per share)	$ 1.02	$ 2.26	$ 0.87	$ 0.72	$ (0.40)	$ 0.60	$ 0.57	$ 0.37	$ 4.83	$ 1.14	$ 3.53
Diluted weighted-average shares outstanding	242,569	249,378	257,177	263,672	263,295	266,989	269,299	272,830	253,237	268,750	272,365
Segment profit margins
Segment profit margin (as a percent)	10.60%	7.70%	9.30%	8.50%	9.00%	8.50%	8.20%	7.10%
Income tax expense charge to reflect provisional estimate of the net impact of Tax Cuts and Jobs Act					$ 266
Income tax benefit	$ 14								$ 14
Disposition of businesses | Tools and Test Equipment
Summary of quarterly data
After tax gain									419
Textron Aviation
Summary of quarterly data
Special charges										$ (28)	$ (35)
Bell
Summary of quarterly data
Special charges										(23)	(5)
Textron Systems
Summary of quarterly data
Special charges										(21)	(62)
Industrial
Summary of quarterly data
Special charges										(58)	(20)
Finance
Summary of quarterly data
Finance Revenue	$ 18	$ 15	$ 17	$ 16	$ 15	$ 18	$ 18	$ 18	66	69	78
Segment profit margins
Segment profit margin (as a percent)	50.00%	20.00%	29.40%	37.50%	40.00%	38.90%	27.80%	22.20%
Manufacturing group
Summary of quarterly data
Income from continuing operations									1,198	247	832
Income from discontinued operations, net of income taxes										1	119
Manufacturing group | Textron Aviation
Summary of quarterly data
Total revenues	$ 1,552	$ 1,133	$ 1,276	$ 1,010	$ 1,391	$ 1,154	$ 1,171	$ 970	4,971	4,686	4,921
Segment profit margins
Segment profit margin (as a percent)	11.00%	8.70%	8.20%	7.10%	8.60%	8.10%	4.60%	3.70%
Manufacturing group | Bell
Summary of quarterly data
Total revenues	$ 827	$ 770	$ 831	$ 752	$ 983	$ 812	$ 825	$ 697	3,180	3,317	3,239
Segment profit margins
Segment profit margin (as a percent)	13.10%	14.70%	14.10%	11.60%	11.60%	13.10%	13.60%	11.90%
Manufacturing group | Textron Systems
Summary of quarterly data
Total revenues	$ 345	$ 352	$ 380	$ 387	$ 489	$ 458	$ 477	$ 416	1,464	1,840	1,756
Segment profit margins
Segment profit margin (as a percent)	10.70%	8.20%	10.50%	12.90%	7.60%	8.70%	8.80%	4.80%
Manufacturing group | Industrial
Summary of quarterly data
Total revenues	$ 1,008	$ 930	$ 1,222	$ 1,131	$ 1,139	$ 1,042	$ 1,113	$ 992	4,291	4,286	3,794
Segment profit margins
Segment profit margin (as a percent)	7.20%	0.10%	6.50%	5.70%	7.30%	4.70%	7.40%	7.70%
Operating Segment
Summary of quarterly data
Segment Profit	$ 397	$ 245	$ 346	$ 279	$ 360	$ 295	$ 295	$ 219	1,267	1,169	1,309
Operating Segment | Finance
Summary of quarterly data
Segment Profit	9	3	5	6	6	7	5	4	23	22	19
Operating Segment | Manufacturing group | Textron Aviation
Summary of quarterly data
Segment Profit	170	99	104	72	120	93	54	36	445	303	389
Operating Segment | Manufacturing group | Bell
Summary of quarterly data
Segment Profit	108	113	117	87	114	106	112	83	425	415	386
Operating Segment | Manufacturing group | Textron Systems
Summary of quarterly data
Segment Profit	37	29	40	50	37	40	42	20	156	139	186
Operating Segment | Manufacturing group | Industrial
Summary of quarterly data
Segment Profit	73	1	80	64	83	49	82	76	218	290	329
Corporate
Summary of quarterly data
Corporate expenses and other, net	(12)	(29)	(51)	(27)	(44)	(30)	(31)	(27)	(119)	(132)	(172)
Special charges											(1)
Reconciling Items | Manufacturing group
Summary of quarterly data
Interest expense, net for Manufacturing group	(34)	$ (32)	$ (35)	$ (34)	(38)	(37)	(36)	(34)	$ (135)	(145)	(138)
2018 Restructuring Plan
Summary of quarterly data
Special charges	(73)
2018 Restructuring Plan | Industrial
Summary of quarterly data
Special charges	$ (73)
2016 Restructuring Plan
Summary of quarterly data
Special charges					(48)	(15)	(12)	(15)		$ (90)	$ (123)
2016 Restructuring Plan | Textron Aviation
Summary of quarterly data
Special charges												$ (63)
2016 Restructuring Plan | Bell
Summary of quarterly data
Special charges												(28)
2016 Restructuring Plan | Textron Systems
Summary of quarterly data
Special charges												(83)
2016 Restructuring Plan | Industrial
Summary of quarterly data
Special charges												(38)
2016 Restructuring Plan | Corporate
Summary of quarterly data
Special charges												$ (1)
Arctic Cat Acquisition
Summary of quarterly data
Special charges					$ 7	$ 10	$ 1	$ 22