Accounts Receivable, Net - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for receivables net current	$ 1,200		$ 778
Allowance for current expected credit losses on accounts receivable	69	$ 39
Adjustment upon Adoption
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for current expected credit losses on accounts receivable
COVID-19
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for current expected credit losses on accounts receivable	$ 11