Restructuring and Other Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	$ 427		$ 435
Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	183		188
Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	244		247
Pratt & Whitney [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	107		107
Collins Aerospace Systems [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	151		157
Eliminations and other [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	169		171
Current Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	444		446
Utilization, foreign exchange and other costs	(51)		(51)
Restructuring Reserve	395	$ 2	395	$ 0
Restructuring and Related Cost, Expected Cost [Abstract]
Expected Costs	484		484
Cost Incurred	444	2
Remaining Costs	38		38
Current Year Actions [Member] | Severance [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	443		445
Utilization, foreign exchange and other costs	(50)		(50)
Restructuring Reserve	395	2	395	0
Current Year Actions [Member] | Facility Exit, Lease Termination and Other Costs
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	1		1
Utilization, foreign exchange and other costs	(1)		(1)
Restructuring Reserve	0	0	0	0
Current Year Actions [Member] | Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	199		200
Current Year Actions [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	245		246
Current Year Actions [Member] | Pratt & Whitney [Member]
Restructuring and Related Cost, Expected Cost [Abstract]
Expected Costs	131		131
Cost Incurred	130	0
Remaining Costs	1		1
Current Year Actions [Member] | Collins Aerospace Systems [Member]
Restructuring and Related Cost, Expected Cost [Abstract]
Expected Costs	184		184
Cost Incurred	146	1
Remaining Costs	37		37
Current Year Actions [Member] | Eliminations and other [Member]
Restructuring and Related Cost, Expected Cost [Abstract]
Expected Costs	169		169
Cost Incurred	168	1
Remaining Costs	0		0
Prior Year Actions [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	(9)		(4)
Utilization, foreign exchange and other costs	(10)		(27)
Restructuring Reserve	27	46	27	58
Restructuring and Related Cost, Expected Cost [Abstract]
Expected Costs	235		235
Cost Incurred	(9)	5		162
Remaining Costs	77		77
Prior Year Actions [Member] | Severance [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	(9)		(6)
Utilization, foreign exchange and other costs	(10)		(24)
Restructuring Reserve	17	36	17	47
Prior Year Actions [Member] | Facility Exit, Lease Termination and Other Costs
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	0		2
Utilization, foreign exchange and other costs	0		(3)
Restructuring Reserve	10	10	10	11
Prior Year Actions [Member] | Cost of Sales [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs			(7)
Prior Year Actions [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs			3
Prior Year Actions [Member] | Pratt & Whitney [Member]
Restructuring and Related Cost, Expected Cost [Abstract]
Expected Costs	121		121
Cost Incurred	(12)	0		133
Remaining Costs	0		0
Prior Year Actions [Member] | Collins Aerospace Systems [Member]
Restructuring and Related Cost, Expected Cost [Abstract]
Expected Costs	112		112
Cost Incurred	3	5		27
Remaining Costs	77		77
Prior Year Actions [Member] | Eliminations and other [Member]
Restructuring and Related Cost, Expected Cost [Abstract]
Expected Costs	2		2
Cost Incurred	0	$ 0		$ 2
Remaining Costs	0		0
Two Years Prior Actions [Member]
Restructuring Cost and Reserve [Line Items]
Net pre-tax restructuring costs	(8)		(7)
Restructuring Reserve	$ 48		$ 48