Business Acquisitions, Dispositions, Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]

Schedule of Goodwill [Table Text Block]

(dollars in millions)	Balance as of January 1, 2017		Goodwill resulting from business combinations		Foreign currency translation and other		Balance as of December 31, 2017
Otis	$	1,575	$	28	$	134	$	1,737
UTC Climate, Controls & Security	9,487		130		392		10,009
Pratt & Whitney	1,511		—		—		1,511
UTC Aerospace Systems	14,483		—		167		14,650
Total Segments	27,056		158		693		27,907
Eliminations and other	3		—		—		3
Total	$	27,059	$	158	$	693	$	27,910

Intangible Assets Disclosure [Table Text Block]

	2017					2016
(dollars in millions)	Gross Amount		Accumulated Amortization			Gross Amount		Accumulated Amortization
Amortized:
Service portfolios	$	2,178	$	(1,534	)	$	1,995	$	(1,344	)
Patents and trademarks	399		(233		)	378		(201		)
Collaboration intangible assets	4,109		(384		)	3,724		(211		)
Customer relationships and other	13,352		(4,100		)	12,798		(3,480		)
	20,038		(6,251		)	18,895		(5,236		)
Unamortized:
Trademarks and other	2,096		—			2,025		—
Total	$	22,134	$	(6,251	)	$	20,920	$	(5,236	)

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

(dollars in millions)	2018		2019		2020		2021		2022
Amortization expense	$	902	$	869	$	888	$	902	$	895