ACCOUNTS RECEIVABLE AND OTHER FINANCIAL ASSETS (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, before Allowance for Credit Loss, Current	$ 620		$ 1,200
Other Receivables, Gross, Current	32		110
Prepaid expense, allowance for credit loss	56		6
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Accounts Receivable, Allowance for Credit Loss	49	$ 51
Provision for expected credit losses and chargebacks	241	38
Accounts Receivable, Allowance for Credit Loss, Writeoff	(11)	(40)
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	3	(1)
Accounts Receivable, Allowance for Credit Loss	282	48
Sales and other expenses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for Other Credit Losses	233	$ 38
COVID-19 [Member] | Merchant revenues
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Provision for expected credit losses and chargebacks	55
Prepaid expenses and other current assets, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Prepaid Expense	130		232
Prepaid expense, allowance for credit loss	12		6
Other assets, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Prepaid Expense	80
Prepaid expense, allowance for credit loss	$ 44		$ 0