Revenues and Contract Costs - Contract with Customer, Asset and Liability (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Disaggregation of Revenue [Line Items]
Contract asset	$ 934	$ 937	$ 1,150
Contract liability	7,229	5,598	$ 5,307
Prepaid expenses and other
Disaggregation of Revenue [Line Items]
Contract asset	739	733
Other Assets
Disaggregation of Revenue [Line Items]
Contract asset	195	204
Other current liabilities
Disaggregation of Revenue [Line Items]
Contract liability	6,053	4,843
Other liabilities
Disaggregation of Revenue [Line Items]
Contract liability	$ 1,176	$ 755