CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Current assets
Cash	$ 327		$ 561	$ 791	$ 543
Short-term investments	178		534
Accounts receivable - net	4,027	$ 3,844	3,943
Intercompany accounts receivable	0		0
Inventory	2,835		2,620
Prepaid expenses and other current assets	500	808	679
Total current assets	7,867		8,337
Property, plant and equipment - net	3,446		3,502
Other noncurrent assets
Goodwill	13,385		13,568
Other intangible assets	4,949		5,265
Deferred income taxes	241	254	253
Investment in subsidiaries	0		0
Intercompany loans receivables	0		0
Other assets	1,740		1,698
Total assets	31,628		32,623
Current liabilities
Short-term debt	82		6
Current portion of long-term debt	426		578
Accounts payable	2,165		2,166
Intercompany accounts payable	0		0
Accrued compensation	427		453
Other current liabilities	2,167	1,905	1,872
Total current liabilities	5,267		5,075
Noncurrent liabilities
Long-term debt	6,737		7,167
Pension liabilities	1,160		1,226
Other postretirement benefits liabilities	344		362
Deferred income taxes	347		538
Intercompany loans payable	0		0
Other noncurrent liabilities	984		965
Total noncurrent liabilities	9,572		10,258
Shareholders’ equity
Eaton shareholders' equity	16,754	$ 17,251	17,253
Noncontrolling interests	35		37
Total equity	16,789		17,290
Total liabilities and equity	31,628		32,623
Consolidating adjustments
Current assets
Cash	0		0	0	0
Short-term investments	0		0
Accounts receivable - net	0		0
Intercompany accounts receivable	(6,673)		(10,704)
Inventory	(84)		(83)
Prepaid expenses and other current assets	17		28
Total current assets	(6,740)		(10,759)
Property, plant and equipment - net	0		0
Other noncurrent assets
Goodwill	0		0
Other intangible assets	0		0
Deferred income taxes	(308)		(324)
Investment in subsidiaries	(105,708)		(138,121)
Intercompany loans receivables	(76,481)		(74,547)
Other assets	0		0
Total assets	(189,237)		(223,751)
Current liabilities
Short-term debt	0		0
Current portion of long-term debt	0		0
Accounts payable	0		0
Intercompany accounts payable	(6,673)		(10,704)
Accrued compensation	0		0
Other current liabilities	(1)		(1)
Total current liabilities	(6,674)		(10,705)
Noncurrent liabilities
Long-term debt	4		2
Pension liabilities	0		0
Other postretirement benefits liabilities	0		0
Deferred income taxes	(308)		(324)
Intercompany loans payable	(76,481)		(74,547)
Other noncurrent liabilities	0		0
Total noncurrent liabilities	(76,785)		(74,869)
Shareholders’ equity
Eaton shareholders' equity	(105,778)		(138,177)
Noncontrolling interests	0		0
Total equity	(105,778)		(138,177)
Total liabilities and equity	(189,237)		(223,751)
Other subsidiaries
Current assets
Cash	276		360	518	438
Short-term investments	178		534
Accounts receivable - net	2,065		2,085
Intercompany accounts receivable	3,194		2,715
Inventory	1,577		1,493
Prepaid expenses and other current assets	333		277
Total current assets	7,623		7,464
Property, plant and equipment - net	1,924		1,941
Other noncurrent assets
Goodwill	5,350		5,547
Other intangible assets	1,727		1,921
Deferred income taxes	236		215
Investment in subsidiaries	25,524		39,873
Intercompany loans receivables	63,179		61,427
Other assets	848		784
Total assets	106,411		119,172
Current liabilities
Short-term debt	13		6
Current portion of long-term debt	0		0
Accounts payable	1,248		1,305
Intercompany accounts payable	1,639		1,403
Accrued compensation	263		260
Other current liabilities	1,034		989
Total current liabilities	4,197		3,963
Noncurrent liabilities
Long-term debt	8		9
Pension liabilities	748		796
Other postretirement benefits liabilities	71		74
Deferred income taxes	174		255
Intercompany loans payable	1,339		1,137
Other noncurrent liabilities	364		378
Total noncurrent liabilities	2,704		2,649
Shareholders’ equity
Eaton shareholders' equity	99,475		112,523
Noncontrolling interests	35		37
Total equity	99,510		112,560
Total liabilities and equity	106,411		119,172
Guarantors
Current assets
Cash	14		18	91	12
Short-term investments	0		0
Accounts receivable - net	1,430		1,376
Intercompany accounts receivable	1,901		5,117
Inventory	789		737
Prepaid expenses and other current assets	35		145
Total current assets	4,169		7,393
Property, plant and equipment - net	683		702
Other noncurrent assets
Goodwill	6,705		6,705
Other intangible assets	3,091		3,206
Deferred income taxes	0		6
Investment in subsidiaries	54,498		73,737
Intercompany loans receivables	6,987		2,909
Other assets	172		166
Total assets	76,305		94,824
Current liabilities
Short-term debt	0		0
Current portion of long-term debt	0		36
Accounts payable	458		328
Intercompany accounts payable	3,756		4,381
Accrued compensation	58		65
Other current liabilities	594		317
Total current liabilities	4,866		5,127
Noncurrent liabilities
Long-term debt	953		976
Pension liabilities	87		89
Other postretirement benefits liabilities	90		96
Deferred income taxes	480		607
Intercompany loans payable	68,714		68,685
Other noncurrent liabilities	265		273
Total noncurrent liabilities	70,589		70,726
Shareholders’ equity
Eaton shareholders' equity	850		18,971
Noncontrolling interests	0		0
Total equity	850		18,971
Total liabilities and equity	76,305		94,824
Eaton Corporation
Current assets
Cash	36		183	181	92
Short-term investments	0		0
Accounts receivable - net	532		482
Intercompany accounts receivable	1,573		2,864
Inventory	553		473
Prepaid expenses and other current assets	115		229
Total current assets	2,809		4,231
Property, plant and equipment - net	839		859
Other noncurrent assets
Goodwill	1,330		1,316
Other intangible assets	131		138
Deferred income taxes	313		356
Investment in subsidiaries	9,689		9,466
Intercompany loans receivables	3,693		7,089
Other assets	720		748
Total assets	19,524		24,203
Current liabilities
Short-term debt	65		0
Current portion of long-term debt	426		542
Accounts payable	459		533
Intercompany accounts payable	1,255		4,916
Accrued compensation	106		128
Other current liabilities	539		566
Total current liabilities	2,850		6,685
Noncurrent liabilities
Long-term debt	5,772		6,180
Pension liabilities	325		341
Other postretirement benefits liabilities	183		192
Deferred income taxes	1		0
Intercompany loans payable	4,585		3,808
Other noncurrent liabilities	355		314
Total noncurrent liabilities	11,221		10,835
Shareholders’ equity
Eaton shareholders' equity	5,453		6,683
Noncontrolling interests	0		0
Total equity	5,453		6,683
Total liabilities and equity	19,524		24,203
Eaton Corporation plc
Current assets
Cash	1		0	$ 1	$ 1
Short-term investments	0		0
Accounts receivable - net	0		0
Intercompany accounts receivable	5		8
Inventory	0		0
Prepaid expenses and other current assets	0		0
Total current assets	6		8
Property, plant and equipment - net	0		0
Other noncurrent assets
Goodwill	0		0
Other intangible assets	0		0
Deferred income taxes	0		0
Investment in subsidiaries	15,997		15,045
Intercompany loans receivables	2,622		3,122
Other assets	0		0
Total assets	18,625		18,175
Current liabilities
Short-term debt	4		0
Current portion of long-term debt	0		0
Accounts payable	0		0
Intercompany accounts payable	23		4
Accrued compensation	0		0
Other current liabilities	1		1
Total current liabilities	28		5
Noncurrent liabilities
Long-term debt	0		0
Pension liabilities	0		0
Other postretirement benefits liabilities	0		0
Deferred income taxes	0		0
Intercompany loans payable	1,843		917
Other noncurrent liabilities	0		0
Total noncurrent liabilities	1,843		917
Shareholders’ equity
Eaton shareholders' equity	16,754		17,253
Noncontrolling interests	0		0
Total equity	16,754		17,253
Total liabilities and equity	$ 18,625		$ 18,175