Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating activities:
Net income	$ 63	$ 68
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of property and equipment, including amortization of internal-use software and website development	14	10
Stock-based compensation expense	16	14
Amortization of intangible assets	7	2
Deferred tax expense	3	1
Excess tax benefits from stock-based compensation	(7)	(11)
Other, net	2	2
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, prepaid expenses and other assets	(71)	(38)
Accounts payable, accrued expenses and other liabilities	4	(5)
Deferred merchant payables	60	34
Income taxes, net	(13)	18
Deferred revenue	21	14
Net cash provided by operating activities	99	109
Investing activities:
Acquisitions, net of cash acquired	(5)
Capital expenditures, including internal-use software and website development	(31)	(20)
Purchases of marketable securities	(32)	(203)
Sales of marketable securities	25	52
Maturities of marketable securities	9	44
Net cash used in investing activities	(34)	(127)
Financing activities:
Proceeds from credit facilities	2	5
Payments to credit facilities		(3)
Principal payments on long-term debt	(10)	(10)
Proceeds from exercise of stock options	8	2
Payment of minimum withholding taxes on net share settlements of equity awards	(13)	(18)
Excess tax benefits from stock-based compensation	7	11
Other, net	3	(1)
Net cash used in financing activities	(3)	(14)
Effect of exchange rate changes on cash and cash equivalents	(12)
Net increase (decrease) in cash and cash equivalents	50	(32)
Cash and cash equivalents at beginning of period	455	351
Cash and cash equivalents at end of period	505	319
Supplemental disclosure of non-cash investing and financing activities:
Capitalization of construction in-process related to build to suit lease obligation	4	14
Capital expenditures incurred but not yet paid primarily related to build to suit lease	$ 8