Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Operating activities:
Net income	$ 226		$ 205		$ 195
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	47	[1]	30	[1]	20	[1]
Stock-based compensation expense	63		49		30
Amortization of intangible assets	18		6		6
Amortization of deferred financing costs	1		1		1
Amortization of discounts and premiums on marketable securities, net	3		5		1
Deferred tax (benefit) expense	(17)		5		(5)
Excess tax benefits from stock-based compensation	(20)		(12)		(3)
Provision (recovery) for doubtful accounts	3		1		(1)
Other, net	11		1		1
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, prepaid expenses and other assets (Note 2)	(26)		(12)		(32)
Accounts payable, accrued expenses and other liabilities	18		17		32
Deferred merchant payables	(9)		17		(1)
Income taxes, net	60		27		(17)
Deferred revenue	9		9		12
Net cash provided by operating activities	387		349		239
Investing activities:
Acquisitions, net of cash acquired	(331)		(35)		(3)
Capital expenditures, including internal-use software and website development	(81)		(55)		(29)
Purchases of marketable securities	(251)		(432)		(219)
Sales of marketable securities	336		175
Maturities of marketable securities	93		151
Distributions proceeds from Expedia related to Spin-Off					7
Net cash used in investing activities	(234)		(196)		(244)
Financing activities:
Repurchase of common stock			(145)
Proceeds from credit facilities	13		10		15
Payments to credit facilities	(3)		(15)		(10)
Principal payments on long-term debt	(40)		(40)		(20)
Proceeds from exercise of stock options and warrants	3		24		231
Payment of minimum withholding taxes on net share settlements of equity awards	(33)		(14)		(7)
Excess tax benefits from stock-based compensation	20		12		3
Payments to purchase subsidiary shares from noncontrolling interest					(22)
Payments on construction in-process related to build to suit lease obligation	(1)		(2)
Net cash (used in) provided by financing activities	(41)		(170)		190
Effect of exchange rate changes on cash and cash equivalents	(8)		1		(1)
Net increase (decrease) in cash and cash equivalents	104		(16)		184
Cash and cash equivalents at beginning of period	351		367		183
Cash and cash equivalents at end of period	455		351		367
Supplemental disclosure of cash flow information
Cash paid during the period for income taxes, net of refunds	54		50		108
Cash paid during the period for interest	7		8		10
Supplemental disclosure of non-cash investing and financing activities:
Capitalization of construction in-process related to build to suit lease obligation	52		8
Capital expenditures incurred but not yet paid primarily related to build to suit lease	10
Non-cash fair value increase for redeemable noncontrolling interests					$ 15

[1] Includes amortization of internal use software and website development costs.