Restructuring and Other Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		$ 25
Restructuring Expense			$ 178
Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			90
Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			62
Other Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			26
Current Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 87		87
Severance Costs	21
Restructuring Reserve, Translation and Other Adjustment	23
Facility Exit, Lease Termination and Other Costs	64
Restructuring Expense	85	28	113
Expected Costs	213		213
Remaining Costs	100		100
Current Year Actions [Member] | Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			57
Current Year Actions [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			30
Current Year Actions [Member] | Other Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			26
Current Year Actions [Member] | Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	27	25	27
Restructuring Reserve, Translation and Other Adjustment	19
Current Year Actions [Member] | Facility Exit, Lease Termination and Other Costs
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	60	0	60
Restructuring Reserve, Translation and Other Adjustment	4
Prior Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	138	164	138
Severance Costs	16
Restructuring Reserve, Translation and Other Adjustment	50
Facility Exit, Lease Termination and Other Costs	8
Restructuring Expense	24	29	53	$ 326
Expected Costs	490		490
Remaining Costs	111		111
Prior Year Actions [Member] | Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			29
Prior Year Actions [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			24
Prior Year Actions [Member] | Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	113	141	113
Restructuring Reserve, Translation and Other Adjustment	44
Prior Year Actions [Member] | Facility Exit, Lease Termination and Other Costs
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	25	23	25
Restructuring Reserve, Translation and Other Adjustment	6
Two Years Prior Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	61		61
Otis [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			31
Otis [Member] | Current Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	13	10
Expected Costs	34		34
Remaining Costs	11		11
Otis [Member] | Prior Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	5	5		35
Expected Costs	51		51
Remaining Costs	6		6
UTC Climate, Controls & Security [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			53
UTC Climate, Controls & Security [Member] | Current Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	8	13
Expected Costs	45		45
Remaining Costs	24		24
UTC Climate, Controls & Security [Member] | Prior Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	14	14		83
Expected Costs	191		191
Remaining Costs	80		80
Pratt & Whitney [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			71
Pratt & Whitney [Member] | Current Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	61	0
Expected Costs	61		61
Remaining Costs	0		0
Pratt & Whitney [Member] | Prior Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	0	1		82
Expected Costs	83		83
Remaining Costs	0		0
UTC Aerospace Systems [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			21
UTC Aerospace Systems [Member] | Current Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	3	5
Expected Costs	73		73
Remaining Costs	65		65
UTC Aerospace Systems [Member] | Prior Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	4	8		105
Expected Costs	142		142
Remaining Costs	25		25
Eliminations and other [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense			2
Eliminations and other [Member] | Prior Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Expense	1	$ 1		$ 21
Expected Costs	23		23
Remaining Costs	$ 0		$ 0