Progress Collections and Deferred Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Progress collections and deferred income (contract liabilities)	$ 3,623		$ 3,623		$ 2,870
Revenue recognized, included in contract liability	501	$ 156	1,314	$ 1,004
Progress collections
Disaggregation of Revenue [Line Items]
Progress collections and deferred income (contract liabilities)	3,503		3,503		2,760
Deferred income
Disaggregation of Revenue [Line Items]
Progress collections and deferred income (contract liabilities)	$ 120		$ 120		$ 110