Acquisitions, Dispositions, Goodwill and Other Intangible Assets Pro Forma Financial Data (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues	$ 18,365,000,000	$ 15,242,000,000
Operating profit	2,045,000,000	1,928,000,000
Rockwell Collins [Member]
Revenues	2,300,000,000
Operating profit	264,000,000
Business Acquisition, Pro Forma Revenue	18,360,000,000	17,320,000,000
Business Acquisition, Pro Forma Net Income	$ 1,484,000,000	$ 1,475,000,000
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 1.74	$ 1.73
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 1.72	$ 1.71
Pro Forma Nonrecurring Adjustment, Amortization of inventory and fixed asset fair value adjustment	$ 141,000,000	$ (5,000,000)
Pro Forma Nonrecurring Adjustment, Amortization of acquired Rockwell Collins intangible assets, net	0	(53,000,000)
Pro Forma Nonrecurring Adjustment, Utilization of contractual customer obligation	0	2,000,000
Pro Forma Nonrecurring Adjustment, UTC/Rockwell fees for advisory, legal, accounting services	2,000,000	26,000,000
Pro Forma Nonrecurring Adjustment, Interest expense incurred on acquisition financing, net	0	(76,000,000)
Pro Forma Nonrecurring Adjustment, Elimination of capitalized pre-production engineering amortization	0	14,000,000
Pro Forma Nonrecurring Adjustment, Adjustment to net periodic pension cost	0	11,000,000
Pro Forma Nonrecurring Adjustment, Adjustment to reflect the adoption of ASC 606	0	29,000,000
Pro Forma Nonrecurring Adjustment, Elimination of entities held for sale	(5,000,000)	(7,000,000)
Pro Forma Nonrecurring Adjustments, Net	$ 138,000,000	$ (59,000,000)