BUSINESS SEGMENT INFORMATION - Summary (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	$ 5,215		$ 3,856		$ 9,907	$ 8,645
Interest expense - net	(37)		(38)		(75)	(72)
Pension and other postretirement benefits income (expense)					(27)	(109)
Restructuring program charges	(13)		(187)		(29)	(187)	$ (214)
Other expense - net	17		(77)		28	(112)
Income before income taxes	620		47		1,158	668
Income tax expense (benefit)	114		(7)		193	176
Net income	506	$ 459	54	$ 438	965	492
Less net income for noncontrolling interests	0		(3)		(1)	(3)
Net income attributable to Eaton ordinary shareholders	506		51		964	489
Electrical Americas
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	1,849		1,490		3,471	3,278
Electrical Global
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	1,418		1,111		2,671	2,255
Hydraulics
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	560		411		1,121	918
Aerospace
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	625		461		1,144	1,141
Vehicle
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	675		327		1,329	925
eMobility
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	88		56		171	128
Operating segments
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	5,215		3,856		9,907	8,645
Segment operating profit (loss)	971		568		1,802	1,326
Operating segments | Electrical Americas
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	1,849		1,490		3,471	3,278
Segment operating profit (loss)	393		308		725	616
Restructuring program charges	(3)		(13)		(8)	(13)
Operating segments | Electrical Global
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	1,418		1,111		2,671	2,255
Segment operating profit (loss)	259		178		472	344
Restructuring program charges	0		(51)		(2)	(51)
Operating segments | Hydraulics
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	560		411		1,121	918
Segment operating profit (loss)	73		37		157	92
Operating segments | Aerospace
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	625		461		1,144	1,141
Segment operating profit (loss)	131		68		227	215
Restructuring program charges	(2)		(30)		(3)	(30)
Operating segments | Vehicle
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	675		327		1,329	925
Segment operating profit (loss)	121		(21)		234	60
Restructuring program charges	(5)		(90)		(11)	(90)
Operating segments | eMobility
Segment Reporting Information, Profit (Loss) [Abstract]
Net sales	88		56		171	128
Segment operating profit (loss)	(6)		(2)		(13)	(1)
Restructuring program charges	(1)		(1)		(1)	(1)
Corporate
Segment Reporting Information, Profit (Loss) [Abstract]
Intangible asset amortization expense	(108)		(88)		(200)	(175)
Interest expense - net	(37)		(38)		(75)	(72)
Pension and other postretirement benefits income (expense)	16		(12)		30	(20)
Restructuring program charges	(2)		(2)		(4)	(2)
Other expense - net	$ (209)		$ (196)		$ (370)	$ (204)