EQUITY - Changes in Shareholders' Equity (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	$ 15,037	$ 14,973	$ 14,288	$ 16,133	$ 14,973	$ 16,133
Net income	506	459	54	438	965	492
Other comprehensive income (loss), net of tax	194	(30)	157	(676)	164	(519)
Cash dividends paid and accrued	(304)	(309)	(293)	(305)
Issuance of shares under equity-based compensation plans	34	5	27	1
Changes in noncontrolling interest of consolidated subsidiaries - net		(2)	2	(3)
Repurchase of shares	(17)	(59)		(1,300)
Balance at end of period	15,450	15,037	14,235	14,288	15,450	14,235
Total Eaton shareholders' equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	14,995	14,930	14,245	16,082	14,930	16,082
Net income	506	458	51	438
Other comprehensive income (loss), net of tax	194	(30)	157	(676)
Cash dividends paid and accrued	(304)	(309)	(292)	(300)
Issuance of shares under equity-based compensation plans	34	5	27	1
Repurchase of shares	(17)	(59)		(1,300)
Balance at end of period	$ 15,408	$ 14,995	$ 14,188	$ 14,245	$ 15,408	$ 14,188
Ordinary shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period (shares)	398.5	398.1	400.0	413.3	398.1	413.3
Balance at beginning of period	$ 4	$ 4	$ 4	$ 4	$ 4	$ 4
Issuance of shares under equity-based compensation plans (shares)	0.2	0.9	0.1	0.9
Repurchase of shares (shares)	(0.1)	(0.5)		(14.2)
Balance at end of period (shares)	398.6	398.5	400.1	400.0	398.6	400.1
Balance at end of period	$ 4	$ 4	$ 4	$ 4	$ 4	$ 4
Capital in excess of par value
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	12,335	12,329	12,203	12,200	12,329	12,200
Issuance of shares under equity-based compensation plans	33	6	25	3
Balance at end of period	12,368	12,335	12,228	12,203	12,368	12,228
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	6,883	6,794	7,007	8,170	6,794	8,170
Net income	506	458	51	438
Cash dividends paid and accrued	(304)	(309)	(292)	(300)
Issuance of shares under equity-based compensation plans	0	(1)	1	(1)
Repurchase of shares	(17)	(59)		(1,300)
Balance at end of period	7,068	6,883	6,767	7,007	7,068	6,767
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	(4,225)	(4,195)	(4,966)	(4,290)	(4,195)	(4,290)
Other comprehensive income (loss), net of tax	194	(30)	157	(676)
Balance at end of period	(4,031)	(4,225)	(4,809)	(4,966)	(4,031)	(4,809)
Shares held in trust
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	(2)	(2)	(3)	(2)	(2)	(2)
Issuance of shares under equity-based compensation plans	1		1	(1)
Balance at end of period	(1)	(2)	(2)	(3)	(1)	(2)
Noncontrolling interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	42	43	43	51	43	51
Net income	0	1	3
Cash dividends paid and accrued	0		(1)	(5)
Changes in noncontrolling interest of consolidated subsidiaries - net		(2)	2	(3)
Balance at end of period	$ 42	$ 42	$ 47	$ 43	$ 42	$ 47