Restructuring and Other Costs (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Sep. 30, 2014
Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       $ 243  
Restructuring Reserve, Two Years Prior Actions 55     55  
Current Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring Reserve Beginning Balance 113        
Net pre-tax restructuring costs 64     215  
Utilization and foreign exchange (56)        
Restructuring Reserve Ending Balance 121 113   121  
Restructuring and Related Cost, Incurred Cost (64) (61) (90)    
Restructuring and Related Cost, Expected Cost 314     314  
Restructuring And Related Cost Expected Remaining 99     99  
Current Year Actions [Member] | Severance [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring Reserve Beginning Balance 112        
Net pre-tax restructuring costs 43        
Utilization and foreign exchange (45)        
Restructuring Reserve Ending Balance 110     110  
Current Year Actions [Member] | Asset Write-Downs [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring Reserve Beginning Balance 0        
Net pre-tax restructuring costs 4        
Utilization and foreign exchange (4)        
Restructuring Reserve Ending Balance 0     0  
Current Year Actions [Member] | Facility Exit, Lease Termination and Other Costs [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring Reserve Beginning Balance 1        
Net pre-tax restructuring costs 17        
Utilization and foreign exchange (7)        
Restructuring Reserve Ending Balance 11     11  
Prior Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring Reserve Beginning Balance 155        
Net pre-tax restructuring costs 0     33  
Utilization and foreign exchange (32)        
Restructuring Reserve Ending Balance 123 155   123  
Restructuring and Related Cost, Incurred Cost 0 (1) (32)   (421)
Restructuring and Related Cost, Expected Cost 480     480  
Restructuring And Related Cost Expected Remaining 26     26  
Prior Year Actions [Member] | Severance [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring Reserve Beginning Balance 132        
Net pre-tax restructuring costs (4)        
Utilization and foreign exchange (26)        
Restructuring Reserve Ending Balance 102     102  
Prior Year Actions [Member] | Asset Write-Downs [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring Reserve Beginning Balance 0        
Net pre-tax restructuring costs 0        
Utilization and foreign exchange 0        
Restructuring Reserve Ending Balance 0     0  
Prior Year Actions [Member] | Facility Exit, Lease Termination and Other Costs [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring Reserve Beginning Balance 23        
Net pre-tax restructuring costs 4        
Utilization and foreign exchange (6)        
Restructuring Reserve Ending Balance 21     21  
Otis [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       53  
Otis [Member] | Current Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost (17) (28) (18)    
Restructuring and Related Cost, Expected Cost 85     85  
Restructuring And Related Cost Expected Remaining 22     22  
Otis [Member] | Prior Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost 0 2 (1)   (69)
Restructuring and Related Cost, Expected Cost 69     69  
Restructuring And Related Cost Expected Remaining 1     1  
UTC Climate, Controls and Security [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       82  
UTC Climate, Controls and Security [Member] | Current Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost (16) (21) (16)    
Restructuring and Related Cost, Expected Cost 97     97  
Restructuring And Related Cost Expected Remaining 44     44  
UTC Climate, Controls and Security [Member] | Prior Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost 2 (2) (24)   (89)
Restructuring and Related Cost, Expected Cost 124     124  
Restructuring And Related Cost Expected Remaining 11     11  
Pratt and Whitney [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       55  
Pratt and Whitney [Member] | Current Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost (8) (10) (37)    
Restructuring and Related Cost, Expected Cost 78     78  
Restructuring And Related Cost Expected Remaining 23     23  
Pratt and Whitney [Member] | Prior Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost 0 1 (6)   (154)
Restructuring and Related Cost, Expected Cost 163     163  
Restructuring And Related Cost Expected Remaining 4     4  
UTC Aerospace Systems [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       36  
UTC Aerospace Systems [Member] | Current Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost (22) (2) (3)    
Restructuring and Related Cost, Expected Cost 37     37  
Restructuring And Related Cost Expected Remaining 10     10  
UTC Aerospace Systems [Member] | Prior Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost (3) (3) (1)   (71)
Restructuring and Related Cost, Expected Cost 88     88  
Restructuring And Related Cost Expected Remaining 10     10  
Sikorsky [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       17  
Sikorsky [Member] | Current Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost (1) 0 (16)    
Restructuring and Related Cost, Expected Cost 17     17  
Restructuring And Related Cost Expected Remaining 0     0  
Sikorsky [Member] | Prior Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Restructuring and Related Cost, Incurred Cost 1 1 0   (38)
Restructuring and Related Cost, Expected Cost 36     36  
Restructuring And Related Cost Expected Remaining 0     0  
Cost Of Sales [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       136  
Cost Of Sales [Member] | Current Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       109  
Cost Of Sales [Member] | Prior Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       29  
Selling General and Administrative [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       107  
Selling General and Administrative [Member] | Current Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       106  
Selling General and Administrative [Member] | Prior Year Actions [Member]
          
Restructuring Cost and Reserve [Line Items]          
Net pre-tax restructuring costs       $ 4