Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities:
Net income (loss)	$ (80)	$ (16)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	29	32
Stock-based compensation expense (Note 8)	29	26
Deferred income tax expense (benefit)	(22)	9
Provision for expected credit losses	2	5
Other, net	4	(2)
Changes in operating assets and liabilities, net of effects from acquisitions and other investments:
Accounts receivable and contract assets, prepaid expenses and other assets	(21)	14
Accounts payable, accrued expenses and other liabilities	(11)	(21)
Deferred merchant payables	36	(86)
Income tax receivables/payables, net	6	(30)
Deferred revenue	9	(1)
Net cash provided by (used in) operating activities	(19)	(70)
Investing activities:
Capital expenditures, including internal-use software and website development	(10)	(20)
Net cash provided by (used in) investing activities	(10)	(20)
Financing activities:
Repurchase of common stock (Note 9)		(115)
Proceeds from issuance of 2026 Senior Notes, net of financing costs (Note 5)	340
Purchase of capped calls in connection with 2026 Senior Notes (Note 5)	(35)
Proceeds from exercise of stock options	7
Payment of withholding taxes on net share settlements of equity awards	(23)	(14)
Payments of finance lease obligation and other financing activities, net	(2)	(1)
Net cash provided by (used in) financing activities	287	570
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(2)	(1)
Net increase in cash, cash equivalents and restricted cash	256	479
Cash, cash equivalents and restricted cash at beginning of period	418	319
Cash, cash equivalents and restricted cash at end of period	$ 674	798
2015 Credit Facility
Financing activities:
Proceeds from 2015 Credit Facility (Note 5)		$ 700