Commitments and Contingencies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 835	$ 835
Other Commitment	11,300
Commercial Aerospace [Member]
Loss Contingencies [Line Items]
Financing and other contractual commitments	13,600	$ 13,400
Other Financing Arrangements [Member]
Loss Contingencies [Line Items]
Other Commitment	4,000
2019 U.S. Defense Contract Management Agency Claim Against Pratt & Whitney [Domain]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	1,730
Loss Contingency, Interest	711
2013 U.S. Defense Contract Management Agency Claim Against Pratt & Whitney [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	177
Loss Contingency, Interest	116
2018 U.S. Defense Contract Management Agency Claim Against Pratt & Whitney [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	269
Loss Contingency, Interest	$ 77