Fair Value Measurements (Fair Value Hierarchy Classification) (Details) (USD $) In Millions, unless otherwise specified																								9 Months Ended		15 Months Ended	9 Months Ended
	Sep. 30, 2014 Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member]	Sep. 30, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] Quoted price in active markets (Level 1) [Member]	Sep. 30, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] Fair Value, Inputs, Level 2 [Member]	Sep. 30, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] Unobservable inputs (Level 3) [Member]	Sep. 30, 2014 Portion at Other than Fair Value Measurement [Member]	Dec. 31, 2013 Portion at Other than Fair Value Measurement [Member]	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Quoted price in active markets (Level 1) [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted price in active markets (Level 1) [Member]	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member] Unobservable inputs (Level 3) [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Unobservable inputs (Level 3) [Member]	Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member]	Dec. 31, 2013 Fair Value, Measurements, Nonrecurring [Member]	Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Quoted price in active markets (Level 1) [Member]	Dec. 31, 2013 Fair Value, Measurements, Nonrecurring [Member] Quoted price in active markets (Level 1) [Member]	Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2013 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]	Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member] Unobservable inputs (Level 3) [Member]	Dec. 31, 2013 Fair Value, Measurements, Nonrecurring [Member] Unobservable inputs (Level 3) [Member]	Sep. 30, 2014 Pratt and Whitney [Member]	Sep. 30, 2013 Pratt and Whitney [Member]	Sep. 30, 2014 Pratt and Whitney [Member]	Sep. 30, 2014 UTC Climate, Controls and Security [Member]	Sep. 30, 2013 UTC Climate, Controls and Security [Member]	Sep. 30, 2014 Sikorsky [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Method Investment, Other than Temporary Impairment																									$ 25				$ 28
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain																								48		23
Available-for-sale securities								863	988	863	988	0	0	0	0
Derivative Assets								100	90	0	0	100	90	0	0
Derivative Liabilities								(217)	(157)	0	0	(217)	(157)	0	0
Business Dispositions																44	66	0	0	44	66	0	0
Long-term receivables	954	586	0	954	0	1,016	655
Customer financing notes receivable	262	366	0	262	0	270	394
Short Term borrowings	(347)	(388)	0	(135)	(212)	(347)	(388)
Long-term debt (excluding capitalized leases)	(21,992)	(21,525)	0	(21,644)	(348)	(19,614)	(19,807)
Long-term liabilities	(268)	(253)	0	(268)	0	(294)	(283)
Gain (Loss) on Disposition of Business																									$ 193		$ 30	$ 38