Advances and Other Receivables - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, allowance for credit loss	$ 42	$ 31	$ 42	$ 31
Financial instruments collection period			39 months
Advances and other receivables reserve
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for credit loss	3	8	$ 4	14
Financing receivable, allowance for credit loss	25	14	25	14
Purchase Discount
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, allowance for credit loss	$ 17	$ 17	$ 17	$ 17