ACCOUNTS RECEIVABLE AND OTHER FINANCIAL ASSETS - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables from customers	$ 1,300		$ 510
Receivables from marketing affiliates	40		32
Provision charged to earnings	44	$ 206
Revenue
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision charged to earnings	13	$ 32
Prepaid expenses, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Prepayments to customers	68		107
Other assets, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Prepayments to customers	$ 35		$ 45