UNAUDITED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Accounts receivable, allowance for credit loss	$ 282	$ 49
Prepaid expense, allowance for credit loss	$ 56	$ 6
Common stock, par value (in dollars per share)	$ 0.008	$ 0.008
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	63,390,891	63,179,471
Treasury stock, shares (in shares)	22,442,328	21,762,070
Short-term Investments
Amortized cost of available-for-sale debt securities	$ 0	$ 998
Prepaid Expenses and Other Current Assets
Prepaid expense, allowance for credit loss	12	6
Long-term Investments
Amortized cost of available-for-sale debt securities	775	2,192
Other Assets [Member]
Prepaid expense, allowance for credit loss	$ 44	$ 0