Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net income (loss)	$ 126	$ 113	$ (19)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation of property and equipment, including amortization of internal-use software and website development	93	82	79
Amortization of intangible assets	33	34	32
Stock-based compensation expense (Note 6)	124	118	96
Deferred income tax expense (benefit) and other, net	14	12	39
Changes in operating assets and liabilities, net of effects from acquisitions and other investments:
Accounts receivable and contract assets, prepaid expenses and other assets	23	(8)	(36)
Accounts payable, accrued expenses and other liabilities	(1)	22
Deferred merchant payables	(3)	14	14
Income tax receivables/payables, net	17	13	38
Deferred revenue	(2)	5	(5)
Net cash provided by operating activities	424	405	238
Investing activities:
Capital expenditures, including internal-use software and website development	(83)	(61)	(64)
Acquisitions and other investments, net of cash acquired (Note 3)	(110)	(24)
Purchases of marketable securities	(133)	(16)	(63)
Sales of marketable securities	80	59	105
Maturities of marketable securities	70	5	28
Other investing activities, net		(12)
Net cash provided by (used in) investing activities	(176)	(49)	6
Financing activities:
Repurchase of common stock (Note 16)	(60)	(100)	(250)
Payment of common stock cash dividends to stockholders (Note 16)	(488)
Payments of finance lease obligation (Note 2)	(5)
Proceeds from exercise of stock options	2	6	3
Payment of withholding taxes on net share settlements of equity awards	(29)	(26)	(17)
Net cash used in financing activities	(580)	(358)	(200)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(4)	(16)	17
Net increase (decrease) in cash, cash equivalents and restricted cash	(336)	(18)	61
Cash, cash equivalents and restricted cash at beginning of period	655	673	612
Cash, cash equivalents and restricted cash at end of period	319	655	673
Supplemental disclosure of cash flow information:
Cash paid during the period for income taxes, net of refunds	47	53	62
Cash paid during the period for interest	6	8	13
Supplemental disclosure of non-cash investing and financing activities:
Stock-based compensation capitalized with internal-use software and website development costs	19	13	13
Equity method investment acquired for non-cash consideration	$ 41
2015 Credit Facility
Financing activities:
Proceeds from credit facility, net of financing costs		5	433
Payments to credit facility		(235)	(296)
Chinese Credit Facilities
Financing activities:
Payments to credit facility		(10)
Proceeds from credit facility		$ 2
2016 Credit Facility
Financing activities:
Payments to credit facility			$ (73)