Tripadvisor (TRIP) 10-Q 8 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 04, 2018
Document And Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Entity Registrant Name	TripAdvisor, Inc.
Trading Symbol	TRIP
Entity Central Index Key	1,526,520
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Common Stock, Unclassified
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		124,603,606
Class B Common Stock
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		12,799,999

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenue (Note 3)		$ 378	$ 372
Costs and expenses:
Cost of revenue	[1]	20	17
Selling and marketing	[2]	198	207
Technology and content	[2]	67	59
General and administrative	[2]	42	35
Depreciation		20	19
Amortization of intangible assets		8	8
Total costs and expenses:		355	345
Operating income		23	27
Other income (expense):
Interest expense		(3)	(3)
Interest income and other, net		1	1
Total other expense, net		(2)	(2)
Income before income taxes		21	25
Provision for income taxes		(16)	(12)
Net income		$ 5	$ 13
Earnings per share attributable to common stockholders (Note 4):
Basic		$ 0.04	$ 0.09
Diluted		$ 0.04	$ 0.09
Weighted average common shares outstanding (Note 4):
Basic		139,312	143,632
Diluted		140,322	144,717
[1]	Excludes amortization as follows:
[2]	Includes stock-based compensation expense as follows

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Costs and expenses:
Amortization of intangible assets	$ 8	$ 8
Depreciation	20	19
Amortization adjustment	17	14
Stock-based compensation:
Stock-based compensation	29	19
Selling and Marketing
Stock-based compensation:
Stock-based compensation	6	5
Technology and Content
Stock-based compensation:
Stock-based compensation	12	7
General and Administrative
Stock-based compensation:
Stock-based compensation	11	7
Acquired Technology
Costs and expenses:
Amortization of intangible assets	2	2
Website Development Costs
Costs and expenses:
Depreciation	$ 15	$ 12

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 5	$ 13
Other comprehensive income:
Foreign currency translation adjustments	[1]	8	7
Total other comprehensive income		8	7
Comprehensive income		$ 13	$ 20
[1]	Foreign currency translation adjustments exclude income taxes due to our intention to indefinitely reinvest the earnings of our foreign subsidiaries in those operations.

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents (Note 6)	$ 635	$ 673
Short-term marketable securities (Note 6)	15	35
Accounts receivable and contract assets, net of allowance for doubtful accounts of $17 and $16, respectively	281	230
Prepaid expenses and other current assets	52	55
Total current assets	983	993
Long-term marketable securities (Note 6)	5	27
Property and equipment, net of accumulated depreciation of $198 and $177, respectively	261	263
Intangible assets, net of accumulated amortization of $120 and $112, respectively	136	142
Goodwill	763	758
Deferred income taxes, net	18	16
Other long-term assets	74	73
TOTAL ASSETS	2,240	2,272
Current liabilities:
Accounts payable	7	8
Deferred merchant payables	269	156
Deferred revenue	101	60
Current portion of debt (Note 7)	7	7
Accrued expenses and other current liabilities	150	141
Total current liabilities	534	372
Long-term debt (Note 7)		230
Deferred income taxes, net	16	14
Other long-term liabilities	300	293
Total Liabilities	850	909
Commitments and contingencies (Note 9)
Stockholders’ equity: (Note 10)
Preferred stock, $0.001 par value Authorized shares: 100,000,000 Shares issued and outstanding: 0 and 0
Additional paid-in capital	946	926
Retained earnings	935	926
Accumulated other comprehensive loss	(34)	(42)
Treasury stock-common stock, at cost, 9,727,140 and 9,474,490 shares, respectively	(457)	(447)
Total Stockholders’ Equity	1,390	1,363
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 2,240	$ 2,272

Condensed Consolidated Balance6

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts	$ 17	$ 16
Property and equipment, accumulated depreciation	198	177
Intangible assets, accumulated amortization	$ 120	$ 112
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	1,600,000,000	1,600,000,000
Common stock, shares issued	136,396,872	135,617,263
Common stock, shares outstanding	126,669,732	126,142,773
Treasury stock, shares	9,727,140	9,474,490
Class B Common Stock
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	12,799,999	12,799,999
Common stock, shares outstanding	12,799,999	12,799,999

Condensed Consolidated Stateme7

Condensed Consolidated Statement of Changes in Stockholders' Equity - 3 months ended Mar. 31, 2018 - USD ($) $ in Millions	Total	Class B Common Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance at Dec. 31, 2017	$ 1,363			$ 926	$ 926	$ (42)	$ (447)
Beginning balance, shares at Dec. 31, 2017	126,142,773	12,799,999	135,617,263				(9,474,490)
Net income	$ 5				5
Cumulative effect adjustment from adoption of new accounting guidance (Note 2)	4				4
Other comprehensive income	8					8
Issuance of common stock related to exercises of options and vesting of RSUs, shares			779,609
Repurchase of common stock	$ (10)						$ (10)
Repurchase of common stock, shares	(252,650)						(252,650)
Withholding taxes on net share settlements of equity awards	$ (12)			(12)
Stock-based compensation	32			32
Ending balance at Mar. 31, 2018	$ 1,390			$ 946	$ 935	$ (34)	$ (457)
Ending balance, shares at Mar. 31, 2018	126,669,732	12,799,999	136,396,872				(9,727,140)

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net income	$ 5	$ 13
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	20	19
Amortization of intangible assets	8	8
Stock-based compensation expense	29	19
Other, net		6
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, prepaid expenses and other assets	(55)	(35)
Accounts payable, accrued expenses and other liabilities		(8)
Deferred merchant payables	110	88
Income tax receivables/payables, net	15
Deferred revenue	42	24
Net cash provided by operating activities	174	134
Investing activities:
Capital expenditures, including internal-use software and website development	(15)	(18)
Purchases of marketable securities	(1)
Sales of marketable securities	41	102
Maturities of marketable securities	3	14
Net cash provided by investing activities	28	98
Financing activities:
Repurchase of common stock	(4)	(150)
Proceeds from exercise of stock options		3
Payment of withholding taxes on net share settlements of equity awards	(12)	(13)
Net cash used in financing activities	(246)	(114)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	6	1
Net (decrease) increase in cash, cash equivalents and restricted cash	(38)	119
Cash, cash equivalents and restricted cash at beginning of period	673	612
Cash, cash equivalents and restricted cash at end of period	635	731
Supplemental disclosure of non-cash investing and financing activities:
Stock-based compensation capitalized with internal-use software and website development costs	3	3
2015 Credit Facility
Financing activities:
Proceeds from credit facility	5	270
Payments to credit facility	$ (235)	(151)
2016 Credit Facility
Financing activities:
Payments to credit facility		$ (73)

Business Description and Basis

Business Description and Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Business Description and Basis of Presentation	NOTE 1: BUSINESS DESCRIPTION AND BASIS OF PRESENTATION We refer to TripAdvisor, Inc. and our wholly-owned subsidiaries as “TripAdvisor”, “the Company”, “us”, “we” and “our” in these notes to the unaudited condensed consolidated financial statements. Description of Business TripAdvisor is an online travel company and our mission is to help people around the world to plan, book and experience the perfect trip. We seek to achieve our mission by providing users and travel partners a global platform about destinations, accommodations, travel activities and experiences, and restaurants that encompasses rich user-generated content, price comparison tools and online reservation and related services. TripAdvisor, Inc., by and through its subsidiaries, owns and operates a portfolio of leading online travel brands. Our flagship brand is TripAdvisor. TripAdvisor-branded websites include tripadvisor.com in the United States and localized versions of the website in 48 markets and 28 languages worldwide. In addition to the flagship TripAdvisor brand, we manage and operate the following 20 other travel media brands, connected by the common goal of providing users the most comprehensive travel-planning and trip-taking resources in the travel industry: www.airfarewatchdog.com, www.bookingbuddy.com, www.citymaps.com, www.cruisecritic.com, www.familyvacationcritic.com, www.flipkey.com, www.thefork.com (including www.lafourchette.com, www.eltenedor.com, www.iens.nl, and www.dimmi.com.au), www.gateguru.com, www.holidaylettings.co.uk, www.holidaywatchdog.com, www.housetrip.com, www.jetsetter.com, www.niumba.com, www.onetime.com, www.oyster.com, www.seatguru.com, www.smartertravel.com, www.tingo.com, www.vacationhomerentals.com, and www.viator.com. We manage our business in two reportable segments: Hotel and Non-Hotel. Our Non-Hotel segment consists of our Experiences, Restaurants, and Rentals offerings. During the quarter we renamed Attractions as “Experiences” and Vacation Rentals as “Rentals.” These changes had no impact on the composition of our segments or on any financial information. For further information on our segments and principal revenue streams within these segments refer to “Note 3: Revenue Recognition Segment Information Basis of Presentation The accompanying unaudited condensed consolidated financial statements present our results of operations, financial position and cash flows on a consolidated basis. The unaudited condensed consolidated financial statements include TripAdvisor, our wholly-owned subsidiaries, and entities we control, or in which we have a variable interest and are the primary beneficiary of expected cash profits or losses. All inter-company accounts and transactions have been eliminated in consolidation. One of our subsidiaries that operates in China has variable interests in affiliated entities in China in order to comply with Chinese laws and regulations, which restrict foreign investment in Internet content provision businesses. Although we do not own the capital stock of these Chinese affiliates, we consolidate their results as we are the primary beneficiary of the cash losses or profits of these variable interest affiliates and have the power to direct the activity of these affiliates. Our variable interest entities’ financials were not material for all periods presented. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and include all normal and recurring adjustments that management of the Company considers necessary for a fair presentation of its financial position and operating results. Accounting Estimates We use estimates and assumptions in the preparation of our unaudited condensed consolidated financial statements in accordance with GAAP. Our estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of our unaudited condensed consolidated financial statements. These estimates and assumptions also affect the reported amount of net income or loss during any period. Our actual financial results could differ significantly from these estimates. The significant estimates underlying our unaudited condensed consolidated financial statements include: (i) recognition and recoverability of goodwill, definite-lived intangibles and other long-lived assets; and (ii) accounting for income taxes. Seasonality Traveler expenditures in the global travel market tend to follow a seasonal pattern. As such, expenditures by travel partners/advertisers to market to potential travelers and, therefore our financial performance, or revenue and profits, tend to be seasonal as well. Our financial performance tends to be seasonally highest in the second and third quarters of a year, as it is a key period for leisure travel research and trip-taking, which includes the seasonal peak in traveler hotel and rental stays, and tours and experiences taken, compared to the first and fourth quarters which represent seasonal low points. Further significant shifts in our business mix or adverse economic conditions could result in future seasonal patterns that are different from historical trends.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	NOTE 2: SIGNIFICANT ACCOUNTING POLICIES New Accounting Pronouncements Not Yet Adopted In June 2016, the Financial Accounting Standard Board (“FASB”) issued new accounting guidance on the measurement of credit losses for financial assets measured at amortized cost, which includes accounts receivable, and available-for-sale debt securities. For financial assets measured at amortized cost, this new guidance requires an entity to: (1) estimate its lifetime expected credit losses upon recognition of the financial assets and establish an allowance to present the net amount expected to be collected; (2) recognize this allowance and changes in the allowance during subsequent periods through net income; and (3) consider relevant information about past events, current conditions and reasonable and supportable forecasts in assessing the lifetime expected credit losses. For available-for-sale debt securities, this new guidance made several targeted amendments to the existing other-than-temporary impairment model, including: (1) requiring disclosure of the allowance for credit losses; (2) allowing reversals of the previously recognized credit losses until the entity has the intent to sell, is more-likely-than-not required to sell the securities or the maturity of the securities; (3) limiting impairment to the difference between the amortized cost basis and fair value; and (4) not allowing entities to consider the length of time that fair value has been less than amortized cost as a factor in evaluating whether a credit loss exists. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted, including interim periods within those fiscal years beginning after December 15, 2018. We are currently considering our timing of adoption and in the process of evaluating the impact of adopting this guidance on our consolidated financial statements and related disclosures. In February 2016, the FASB issued new guidance related to accounting for leases. The new standard requires the recognition of assets (right-of-use-assets) and liabilities arising from lease transactions on the balance sheet and the disclosure of key information about leasing arrangements. Accordingly, a lessee will recognize a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. Both the asset and liability will initially be measured at the present value of the future minimum lease payments over the lease term. The new guidance will classify leases as either finance or operating leases, with classification determining the presentation of expenses and cash flows on our consolidated financial statements. Initial costs directly attributable to negotiating and arranging the lease will be included in the asset. We continue to evaluate the new lease guidance and are in the process of updating accounting policies, accounting position memos, and evaluating our existing population of contracts to ensure all contracts that meet the definition of a lease contract under the new standard are identified. We are also in the process of implementing additional lease software to support our accounting and reporting process, including the new quantitative and qualitative financial disclosure requirements. In addition, we are evaluating the impact of the system implementation and new accounting guidance on our internal controls. We will continue to provide updates on our assessment of the effect that this new lease guidance will have on our consolidated financial statements, disclosures, systems and related internal controls, and will disclose material effects, if any, when known. Recently Adopted Accounting Pronouncements In May 2017, the FASB issued new accounting guidance that clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications which will reduce diversity in practice. Under the new guidance, an entity will not apply modification accounting to a share-based payment award if the award’s fair value (or calculated value or intrinsic value, if those measurement methods are used), the award’s vesting conditions, and the award’s classification as an equity or liability instrument are the same immediately before and after the change. The guidance also states that an entity is not required to estimate the value of the award immediately before and after the change if the change does not affect any of the inputs to the model used to value the award. We adopted this guidance prospectively in the first quarter of 2018. We believe the new guidance will likely result in fewer changes to the terms of an award being accounted for as modifications. In January 2017, the FASB issued new accounting guidance to clarify the definition of a business and provide additional guidance to assist entities with evaluating whether transactions should be accounted for as asset acquisitions (or asset disposals) or business combinations (or disposals of a business). Under this new guidance, an entity first determines whether substantially all of the fair value of the assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets. If this criterion is met, the transaction should be accounted for as an asset acquisition as opposed to a business combination. This distinction is important because the accounting for an asset acquisition significantly differs from the accounting for a business combination. This new guidance eliminates the requirement to evaluate whether a market participant could replace missing elements (e.g. inputs or processes), narrows the definition of outputs and requires that a business include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create outputs. We adopted this guidance in the first quarter of 2018 and it will be applied prospectively to any transactions occurring within and after the adoption date. In November 2016, the FASB issued new accounting guidance on the classification and presentation of restricted cash in the statement of cash flows to address the diversity in practice. This new guidance requires entities to show changes in cash, cash equivalents and restricted cash on a combined basis in the statement of cash flows. In addition, this accounting guidance requires a reconciliation of the total cash, cash equivalent and restricted cash in the statement of cash flows to the related captions in the balance sheet if cash, cash equivalents and restricted cash are presented in more than one line item in the balance sheet. We adopted this guidance in the first quarter of 2018 and applied it retrospectively to all prior periods presented in the financial statements as required under the new guidance. The adoption did not have a material impact on our consolidated financial statements and related disclosures. In October 2016, the FASB issued new accounting guidance on income tax accounting associated with intra-entity transfers of assets other than inventory. This accounting update, which is part of the FASB's simplification initiative, is intended to reduce diversity in practice and the complexity of tax accounting, particularly for those transfers involving intellectual property. This new guidance requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. We adopted this new guidance in the first quarter of 2018 on a modified retrospective basis. Accordingly, we recognized the cumulative effect of initial application of this new guidance as an adjustment to the opening balance of retained earnings, which was not material to our consolidated financial statements. In August 2016, the FASB issued new accounting guidance which clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. The new guidance specifically addresses the following cash flow topics in an effort to reduce diversity in practice: (1) debt prepayment or debt extinguishment costs; (2) settlement of zero-coupon bonds; (3) contingent consideration payments made after a business combination; (4) proceeds from the settlement of insurance claims; (5) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; (6) distributions received from equity method investees; (7) beneficial interests in securitization transactions; and (8) separately identifiable cash flows and application of the predominance principle. We adopted this new guidance in the first quarter of 2018 retrospectively and the adoption did not have an impact on our consolidated financial statements and related disclosures. In January 2016, the FASB issued new accounting guidance which amends the standard on the recognition and measurement of financial instruments. The FASB clarified certain aspects of this guidance by issuing an update for technical corrections and improvements related to this guidance in February 2018. The guidance (1) requires an entity to measure equity investments (except those accounted for under the equity method or those that result in consolidation of the investee) at fair value with changes in fair value recognized in net income rather than accumulated other comprehensive income on the balance sheet; (2) allows an entity to elect to measure the equity investments that do not have a readily determinable fair value using a new measurement alternative which measure these equity investments at cost less impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer; (3) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; and (4) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s evaluation of their other deferred tax assets. We adopted this guidance in the first quarter of 2018 and elected to prospectively account for our investments in equity securities of privately-held companies that do not have a readily determinable fair value using In May 2014, the FASB issued new accounting guidance on revenue from contracts with customers, or ASC 606, Revenue from Contracts with Customers In the first quarter of 2018, we adopted ASC 606 under the modified retrospective method for all contracts that were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under the new revenue guidance, while prior period amounts are not adjusted and continue to be reported in accordance with our previous accounting policies under the historical revenue guidance, or ASC 605, Revenue Recognition We evaluated each of our revenue streams and applied ASC 606 as further discussed in “Note 3: Revenue Recognition We recognized the cumulative effect of initial application of ASC 606 as an adjustment to the opening balance of retained earnings. We recorded a net increase in opening retained earnings of $4 million as of January 1, 2018 due to the cumulative impact of adoption of the new revenue guidance and all other accounts were not materially impacted. There have been no changes to our significant accounting policies since December 31, 2017, other than noted above. See “Note 3: Revenue Recognition Significant Accounting Policies

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Revenue Recognition	NOTE 3: REVENUE RECOGNITION Revenue Recognition under ASC 606 We generate all of our revenue from contracts with customers. We recognize revenue when we satisfy a performance obligation by transferring control of the promised services to a customer in an amount that reflects the consideration that we expect to receive in exchange for those services. When we act as an agent in the transaction under ASC 606, we recognize revenue for only our commission on the arrangement. We determine revenue recognition through the following steps: (1) Identification of the contract, or contracts, with a customer (2) Identification of the performance obligations in the contract (3) Determination of the transaction price (4) Allocation of the transaction price to the performance obligations in the contract (5) Recognition of revenue when, or as, we satisfy a performance obligation. At contract inception, we assess the services promised in our contracts with customers and identify a performance obligation for each promise to transfer to the customer a service (or bundle of services) that is distinct. To identify the performance obligations, we consider all of the services promised in the contract regardless of whether they are explicitly stated or are implied by customary business practices. We have provided qualitative information about our performance obligations for our principal revenue streams discussed below. There was no significant revenue recognized in the three months ended March 31, 2018 related to performance obligations satisfied in prior periods. We have applied a practical expedient and do not disclose the value of unsatisfied performance obligations that have an original expected duration of less than one year, and we do not have any material unsatisfied performance obligations over one year. The value related to our remaining or partially satisfied performance obligations relates to subscription services that are satisfied over time or services that are recognized at a point in time, but not yet achieved. Our timing of services, invoicing and payments are discussed in more detail below and do not include a significant financing component. Our customer invoices are generally due 30 days from the time of invoicing. We recognize an asset for the incremental costs of obtaining a contract with a customer if we expect the benefit of those costs to be longer than one year. We have determined that certain sales incentive programs meet the requirements to be capitalized. Total capitalized costs to obtain a contract were approximately $1 million as of March 31, 2018. We amortize these contract costs on a straight-line basis over the estimated customer life, which is based on historical data. Amortization expense recorded to sales and marketing during the three months ended March 31, 2018 was not material. We assess such assets for impairment when events or circumstances indicate that the carrying amount may not be recoverable. The recognition of revenue may require the application of judgment related to the determination of the performance obligations, the timing of when the performance obligations are satisfied and other areas. The determination of our performance obligations does not require significant judgment given that we generally do not provide multiple services to a customer in a given transaction, and the point in which control is transferred to the customer is readily determinable. In instances where we recognize revenue over time, we generally have either a subscription service that is recognized over time on a straight-line basis using the time-elapsed output method, or based on other output measures that provide a faithful depiction of the transfer of our services. When an estimate for cancellations is included in the transaction price, we base our estimate on historical data. The estimate is not material. Taxes assessed by a government authority that are both imposed on and concurrent with a specific revenue –producing transaction, that are collected by us from a customer, are reported on a net basis, or in other words excluded from revenue on our consolidated financial statements, which is consistent with prior periods. The application of our revenue recognition policies and a description of our principal activities, organized by segment, from which we generate our revenue, are presented below. Hotel Segment TripAdvisor-branded Click-based Advertising and Transaction Revenue . Our largest source of Hotel segment revenue is generated from click-based advertising on TripAdvisor-branded websites, which is primarily comprised of contextually-relevant booking links to our travel partners’ sites. Our click-based travel partners are predominantly online travel agencies, or OTAs, and direct suppliers in the hotel category. Click-based advertising is generally priced on a cost-per-click, or “CPC”, basis, with payments from advertisers determined by the number of users who click on a link multiplied by the price that partner is willing to pay for that click, or hotel shopper lead. CPC rates that our travel partners are willing to pay are determined in a dynamic, competitive auction process, or metasearch auction. We record click-based advertising revenue as the click occurs and traveler leads are sent to the travel partner websites as our performance obligation is fulfilled at that time. Click-based revenue is generally billed to our travel partners on a monthly basis consistent with the timing of the service. Transaction revenue is generated from our instant booking feature, which enables hotel shoppers to book directly with a travel partner, or the merchant of record, without leaving our website. We earn a commission from our travel partner for a user that completes a hotel reservation on our website. Our instant booking revenue includes arrangements where commissions are billable on all instant booking hotel reservations and also includes arrangements where the commission is billable only upon the completion of the traveler’s stay resulting from the reservation. Our performance obligation in both arrangements is complete at the time of the booking and the commission earned is recognized upon booking, as we have no post-booking service obligations. The amount of revenue recognized for commissions which are billable contingent upon a travelers stay requires an estimate of the impact of cancellations using historical cancellation rates. Contract assets are recognized at the time of booking for commissions that are billable at the time of stay. We are the agent in these transactions under ASC 606. TripAdvisor-branded Display-based Advertising and Subscription Revenue . Travel partners can promote their brands in a contextually-relevant manner through a variety of display-based advertising placements on our websites. Our display-based advertising clients are predominately direct suppliers of hotels, airlines and cruises, as well as destination marketing organizations. We also sell display-based advertising to OTAs and other travel related businesses, as well as advertisers from non-travel categories. Display-based advertising is sold predominantly on a cost per thousand impressions, or CPM, basis. The performance obligation in our display-based advertising business is to display a number of advertising impressions on our websites and we recognize revenue for impressions as they are delivered. Services are generally billed monthly. We have applied the practical expedient to measure progress toward completion, as we have the right to invoice the customer in an amount that directly corresponds with the value to the customer of our performance to date, which is measured based on impressions delivered. In addition, we offer subscription-based advertising to hotels, B&Bs and other specialty lodging properties. Our performance obligation is generally to enable subscribers to advertise their business on our website, including such information as a website URL, email address and phone number, as well as other information. Subscription advertising is predominantly sold for a flat fee, for a contracted period of time which is predominately one year or less. Subscription advertising services are generally billed in advance of service. Subscription advertising revenues are recognized on a straight-line basis over the period of the subscription service as efforts are expended evenly throughout the contract period. When prepayments are received, we recognize deferred revenue for the amount of prepayment in excess of revenue recognized until the performance obligation is satisfied. Other Hotel Revenue. Our other hotel revenue primarily includes revenue from non-TripAdvisor-branded websites, such as www.bookingbuddy.com, www.cruisecritic.com, and www.onetime.com, which primarily includes click-based advertising and display-based advertising revenue. The performance obligations and timing of customer payments for these brands and methods of recognizing revenue are generally consistent with click-based advertising or display-based advertising revenue, as described above. Non-Hotel Segment We provide information and services for users to research, book and experience activities and attractions in popular travel destinations both through Viator, our dedicated Experiences offering, and on our TripAdvisor website and applications. We also power travel activities and experiences booking capabilities to users for affiliate partners, including some of the world’s top airlines, hotel chains and online and offline travel agencies. We work with local tour or travel activities/experiences operators (“the supplier”) to provide our users with access to book tours, activities and experiences (“the activity”) in popular destinations worldwide. We generate commissions for each booking transaction we facilitate through our online reservation system. We provide post-booking service to the user until the time of the activity, which is the completion of the performance obligation. Revenue is recognized at the time that the activity occurs. We are an agent in the transaction, under ASC 606, for nearly all of these transactions. We generally collect payment from the user at the time of booking that includes both our commission revenue and the amount due to the supplier. Our commission revenue is recorded as deferred revenue until revenue is recognized, and the amount due to the supplier is recorded to deferred merchant payables on our consolidated balance sheet, until payment is made to the supplier after the completion of the activity. To a lesser extent, we earn commissions from third-party merchant partners, who display and promote our supplier activities on their websites to generate bookings. In these transactions, where we are not the merchant of record, we generally invoice and receive commissions directly from the third-party merchant partners. Our performance obligation is to allow the third-party merchant partners to display and promote our supplier activities on their website and we earn a commission when users book and complete an activity. Our performance obligation is complete and revenue is recognized at the time of the booking, as we have no post-booking obligations. We recognize this revenue net of an estimate of the impact of cancellations using historical cancellation rates. Contract assets are recognized for commissions that are billable contingent upon completion of the activity. We are an agent in these transactions, under ASC 606. We also provide information and services for users to research and book restaurants in popular travel destinations through our dedicated restaurant reservations offering, TheFork, and on our TripAdvisor website and applications. TheFork is an online restaurant booking platform operating on a number of websites (including www.lafourchette.com, www.eltenedor.com, www.iens.nl and www.dimmi.com.au), with a network of restaurant partners located primarily across Europe and Australia. Our bookable restaurants are available on www.thefork.com and on TripAdvisor-branded websites and mobile applications. We primarily generate transaction fees (or per seated diner fees) that are paid by restaurants for diners seated primarily from bookings through TheFork’s online reservation system. The transaction fee is recognized in revenue after the reservation is fulfilled, or as diners are seated by our restaurant customers. Revenue is billed monthly when the transaction fees are payable, which is at the time the diner is seated. To a lesser extent, we also generate subscription fees for access to certain online reservation management services and marketing analytic tools provided by TheFork and TripAdvisor. As the performance obligation is to provide restaurants with access to these services over the subscription period, subscription fee revenue is recognized over the period of the subscription service on a straight-line basis as efforts are expended evenly throughout the contract period. Subscription fees are generally billable in advance of service. When prepayments are received, we recognize deferred revenue for the amount of prepayment in excess of revenue recognized until the performance obligation is satisfied. In addition, we provide information and services for users to research and book vacation and short-term rental properties, including full home rentals, condominiums, villas, beach rentals, cabins and cottages. Rentals generates revenue primarily by offering individual property owners and managers the ability to list their properties on our websites and mobile applications thereby connecting homeowners with travelers through a free-to-list, commission-based option or, to a lesser extent, by an annual subscription-based fee structure. These properties are listed on www.flipkey.com, www.holidaylettings.co.uk, www.housetrip.com, www.niumba.com, and www.vacationhomerentals.com, and on our TripAdvisor-branded websites and mobile applications. We earn commissions associated with rental transactions through our free-to-list model from both the traveler and the property owner or manager. We provide post-booking service to the traveler and property owners and managers until the time the rental commences, which is the time the performance obligation is completed. Revenue from transaction fees is recognized at the time that the rental commences. We are an agent in these transactions, under ASC 606. We generally collect payment from the traveler at the time of booking that includes our commissions, which is recorded as deferred revenue until revenue is recognized, and the amount due to the property owner, which is recorded in deferred merchant payables on our consolidated balance sheet, until payment is made to the property owner after the completion of the rental. Payments for term-based subscription fees related to online advertising services for the listing of rental properties are generally due in advance. As the performance obligation is the listing service provided to the property owner or manager over the subscription period, revenue is recognized over the period of the subscription service on a straight-line basis as efforts are expended evenly throughout the contract period. We recognize deferred revenue for the amount of prepayment in excess of revenue recognized until the performance obligation is satisfied. Practical Expedients and Exemptions We expense costs to obtain a contract as incurred, such as sales commissions, when the amortization period would have been one year or less. We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed. Impact of Adoption of ASC 606 The impact of this new revenue recognition guidance on our unaudited condensed consolidated statement of operations for the three months ended March 31, 2018 was as follows: As Reported - ASC 606 March 31, 2018 Impact of Accounting under ASC 606 Adjusted - ASC 605 March 31, 2018 (in millions) Revenue $ 378 $ (4 ) $ 374 Operating income 23 (4 ) 19 Income before income taxes 21 (4 ) 17 Provision for income taxes (16 ) 1 (15 ) Net income 5 (3 ) 2 The impact of the new guidance was not meaningful as of and for the three months ended March 31, 2018 for the unaudited condensed consolidated balance sheet and unaudited condensed consolidated statement of cash flows, respectively. Disaggregation of Revenue We disaggregate revenue from contracts with customers into major products/revenue sources. We have determined that disaggregating revenue into these categories achieves the disclosure objective to depict how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. As noted in “Note 12: Segment Information Three months ended March 31, 2018 Major products/revenue sources: (in millions) Click-based advertising and transaction revenue $ 189 Display-based advertising and subscription revenue 71 Other hotel revenue 39 Total Hotel Revenue (1) 299 Non-Hotel Revenue (1) 79 Total Revenue $ 378 (1) Our revenue is recognized primarily at a point in time for both our Hotel and Non-Hotel segments. Contract balances The following table provides information about the opening and closing balances of accounts receivables and contract assets from contracts with customers (in millions): March 31, 2018 December 31, 2017 Accounts receivable $ 269 $ 230 Contract assets 12 - Total $ 281 $ 230 Accounts receivable are recognized when the right to consideration becomes unconditional. Contract assets are rights to consideration in exchange for services that we have transferred to a customer when that right is conditional on something other than the passage of time, such as commission payments that are contingent upon the completion of the service by the principal in the transaction. Contract liabilities generally include payments received in advance of performance under the contract, and are realized as revenue as the performance obligation to the customer is satisfied, which we present as deferred revenue on our unaudited condensed consolidated balance sheet. During the three months ended March 31, 2018, $41 million was recognized as revenue which was included in the deferred revenue balance at the beginning of the period. The difference between the opening and closing balances of our contract assets and deferred revenue primarily results from the timing differences between our performance and the customer’s payment. There were no significant changes in contract assets or liabilities during the three months ended March 31, 2018 related to business combinations, impairments, cumulative catch-up or other material adjustments.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 4: EARNINGS PER SHARE Basic Earnings Per Share Attributable to Common Stockholders We compute basic earnings per share, or Basic EPS, by dividing net income by the weighted average number of common shares outstanding during the period. We compute the weighted average number of common shares outstanding during the reporting period using the total of common stock and Class B common stock outstanding as of the last day of the previous year end reporting period plus the weighted average of any additional shares issued and outstanding less the weighted average of any common shares repurchased during the reporting period. Diluted Earnings Per Share Attributable to Common Stockholders Diluted earnings per share, or Diluted EPS, includes the potential dilution of common equivalent shares outstanding that could occur from stock-based awards and other stock-based commitments using the treasury stock method. We compute Diluted EPS by dividing net income by the sum of the weighted average number of common and common equivalent shares outstanding during the period. We computed the weighted average number of common and common equivalent shares outstanding during the period using the sum of (i) the number of shares of common stock and Class B common stock used in the basic earnings per share calculation as indicated above, and (ii) if dilutive, the incremental weighted average common stock that we would issue upon the assumed exercise of outstanding common equivalent shares, primarily related to stock options and the vesting of restricted stock units using the treasury stock method, and (iii) if dilutive, performance-based and market-based awards based on the number of shares that would be issuable as of the end of the reporting period assuming the end of the reporting period was also the end of the contingency period. Under the treasury stock method, the assumed proceeds calculation includes the actual proceeds to be received from the employee upon exercise of outstanding equity awards and the average unrecognized compensation cost during the period. The treasury stock method assumes that a company uses the proceeds from the exercise of an equity award to repurchase common stock at the average market price for the reporting period. Below is a reconciliation of the weighted average number of shares of common stock outstanding in calculating Diluted EPS (shares in thousands and dollars in millions, except per share amounts) for the periods presented: Three months ended March 31, 2018 2017 Numerator: Net income $ 5 $ 13 Denominator: Weighted average shares used to compute Basic EPS 139,312 143,632 Weighted average effect of dilutive securities: Stock options 118 516 RSUs/MSUs 892 569 Weighted average shares used to compute Diluted EPS 140,322 144,717 Basic EPS $ 0.04 $ 0.09 Diluted EPS $ 0.04 $ 0.09 Potential common shares, consisting of outstanding stock options, restricted stock units (“RSUs”) and market-based stock units (“MSUs”), totaling approximately 12.0 million shares and 6.4 million shares for the three months ended March 31, 2018 and 2017, respectively, have been excluded from the calculation of Diluted EPS because their effect would have been antidilutive. In addition, potential common shares, consisting of performance-based awards, totaling approximately 0.4 million shares and 0.1 million shares for three months ended March 31, 2018 and 2017, respectively, for which all targets required to trigger vesting had not been achieved, were excluded from the calculation of weighted average shares used to compute Diluted EPS for those reporting periods. The earnings per share amounts are the same for common stock and Class B common stock because the holders of each class are legally entitled to equal per share distributions whether through dividends or in liquidation.

Stock Based Awards and Other Eq

Stock Based Awards and Other Equity Instruments	3 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Awards and Other Equity Instruments	NOTE 5: STOCK BASED AWARDS AND OTHER EQUITY INSTRUMENTS Stock-Based Compensation Expense The following table presents the amount of stock-based compensation expense related to stock-based awards, primarily stock options and RSUs, on our unaudited condensed consolidated statements of operations during the periods presented: Three months ended March 31, 2018 2017 (in millions) Selling and marketing $ 6 $ 5 Technology and content 12 7 General and administrative 11 7 Total stock-based compensation 29 19 Income tax benefit from stock-based compensation (7 ) (7 ) Total stock-based compensation, net of tax effect $ 22 $ 12 During both the three months ended March 31, 2018 and 2017, we capitalized $3 million of stock-based compensation expense as internal-use software and website development costs. Stock-Based Award Activity and Valuation 2018 Stock Option Activity During the three months ended March 31, 2018, we granted 611,235 service-based non-qualified stock options under the Company’s 2011 Stock and Annual Incentive Plan, as amended (the “2011 Incentive Plan”). These stock options generally have a term of ten years from the date of grant and typically vest equally over a four-year requisite service period. A summary of our stock option activity during the three months ended March 31, 2018, is presented below: Weighted Weighted Average Average Exercise Remaining Aggregate Options Price Per Contractual Intrinsic Outstanding Share Life Value (in thousands) (in years) (in millions) Options outstanding at December 31, 2017 6,853 $ 52.78 Granted 611 41.54 Exercised (1) (196 ) 28.21 Cancelled or expired (72 ) 47.80 Options outstanding at March 31, 2018 7,196 $ 52.48 6.7 $ 10 Exercisable as of March 31, 2018 3,428 $ 54.81 4.7 $ 5 Vested and expected to vest after March 31, 2018 (2) 7,196 $ 52.48 6.7 $ 10 (1) Inclusive of 150,855 of options which were not converted into shares due to net share settlement in order to cover the aggregate exercise price and the required amount of employee withholding taxes. Potential shares that had been convertible under stock options that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the unaudited condensed consolidated statements of cash flows. (2) The Company accounts for forfeitures as they occur, rather than estimate expected forfeitures as allowed under GAAP and therefore do not include a forfeiture rate in our vested and expected to vest calculation unless necessary for a performance condition award. Aggregate intrinsic value represents the difference between the closing stock price of our common stock and the exercise price of outstanding, in-the-money options. Our closing stock price as reported on NASDAQ as of March 31, 2018 was $40.89. The total intrinsic value of stock options exercised was $3 million and $7 million, The fair value of stock option grants under the 2011 Incentive Plan has been estimated at the date of grant using the Black–Scholes option pricing model with the following weighted average assumptions for the periods presented: Three months ended March 31, 2018 2017 Risk free interest rate 2.66 % 1.91 % Expected term (in years) 5.45 5.35 Expected volatility 42.29 % 41.53 % Expected dividend yield — % — % The weighted-average grant date fair value of options granted was $17.60 and $17.20 for the three months ended March 31, 2018 and 2017, respectively. The total fair value of stock options vested was $8 million and $13 million for the three months ended March 31, 2018 and 2017, respectively. Cash received from stock option exercises was not material and $3 million for the three months ended March 31, 2018 and 2017, respectively. 2018 RSU Activity During the three months ended March 31, 2018, we granted 2,590,380 service-based RSUs under the 2011 Incentive Plan which typically vest over a four-year requisite service period. A summary of our RSU activity for service-based and performance-based awards during the three months ended March 31, 2018, is presented below: Weighted Average Grant- Aggregate RSUs Date Fair Intrinsic Outstanding Value Per Share Value (in thousands) (in millions) Unvested RSUs outstanding as of December 31, 2017 (1) 6,015 $ 48.14 Transfer (1) (213 ) 30.04 Granted 2,590 41.44 Vested and released (2) (1,007 ) 56.11 Cancelled (160 ) 47.26 Unvested RSUs outstanding as of March 31, 2018 7,225 $ 45.18 $ 295 Expected to vest after March 31, 2018 (3) 7,225 $ 45.18 $ 295 (1) RSUs outstanding as of December 31, 2017 include 213,000 MSUs awarded to the Company’s CEO in November 2017. This award has been transferred to the MSU activity table below. (2) Inclusive of 269,878 RSUs withheld due to net share settlement to satisfy required employee tax withholding requirements. Potential shares which had been convertible under RSUs that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the unaudited condensed consolidated statements of cash flows. (3) The Company accounts for forfeitures as they occur, rather than estimate expected forfeitures as allowed under GAAP and therefore do not include a forfeiture rate in our expected to vest calculation unless necessary for a performance condition award. A summary of our RSU activity for MSUs, during the three months ended March 31, 2018 is presented below: Weighted Average Grant- Aggregate MSUs Date Fair Intrinsic Outstanding Value Per Share Value (in thousands) (in millions) Unvested MSUs outstanding as of December 31, 2017 (1) 213 $ 30.04 Granted (2) 71 59.40 Vested and released ― ― Cancelled ― ― Unvested MSUs outstanding as of March 31, 2018 284 $ 37.41 $ 12 (1) (2) MSUs provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2018 through December 31, 2020 relative to the TSR performance of the Nasdaq Composite Total Return Index. A Monte-Carlo simulation model, which simulated the present value of the potential outcomes of future stock prices and TSR of the Company and the Nasdaq Composite Total Return Index over the performance period, was used to calculate the grant-date fair value of these awards. The estimated grant-date fair value of these awards is being amortized on a straight-line basis over the requisite service period through December 31, 2020. Based upon actual attainment relative to the target performance metric, the grantee has the ability to receive up to 200% of the target number of MSUs originally granted, or to be issued none at all. These MSUs were granted under the 2011 Incentive Plan. Total current income tax benefits associated with the exercise or settlement of TripAdvisor stock-based awards held by our employees were $3 million and $14 million during the three months ended March 31, 2018 and 2017, respectively. Unrecognized Stock-Based Compensation A summary of our remaining unrecognized stock-based compensation expense and the weighted average remaining amortization period at March 31, 2018 related to our non-vested equity awards is presented below (in millions, except in years information): Stock Options RSUs MSUs Unrecognized compensation expense $ 55 $ 302 $ 10 Weighted average period remaining (in years) 3.0 3.2 2.8

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2018
Investments All Other Investments [Abstract]
Financial Instruments	NOTE 6: FINANCIAL INSTRUMENTS Cash, Cash Equivalents, Restricted Cash and Marketable Securities The following tables show our cash, cash equivalents, restricted cash and short-term and long-term available-for-sale marketable debt securities, by major security type, that are measured at fair value on a recurring basis and were categorized using the fair value hierarchy, as well as their classification on March 31, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash, Cash Equivalents and Restricted Cash Short-Term Marketable Securities Long-Term Marketable Securities Cash and restricted cash (1) $ 340 $ — $ — $ 340 $ 340 $ — $ — Level 1: Money market funds 295 — — 295 295 — — Level 2: U.S. agency securities 4 — — 4 — 4 — Certificates of deposit 2 — — 2 — 2 — Corporate debt securities 14 — — 14 — 9 5 Subtotal 20 — — 20 — 15 5 Total $ 655 — — $ 655 $ 635 $ 15 $ 5 December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash, Cash Equivalents and Restricted Cash Short-Term Marketable Securities Long-Term Marketable Securities Cash and restricted cash (1) $ 663 $ — $ — $ 663 $ 663 $ — $ — Level 1: Money market funds 1 — — 1 1 — — Level 2: U.S. agency securities 11 — — 11 — 6 5 U.S. treasury securities 1 — — 1 — 1 — Certificates of deposit 2 — — 2 — 2 — Commercial paper 11 — — 11 9 2 — Corporate debt securities 46 — — 46 — 24 22 Subtotal 71 — — 71 9 35 27 Total $ 735 — — $ 735 $ 673 35 27 (1) As of March 31, 2018 and December 31, 2017, our restricted cash which primarily consists of escrowed security deposits, was not material and is included in other long-term assets on our unaudited condensed consolidated balance sheets. Our cash and cash equivalents consist of cash on hand in global financial institutions, money market funds and marketable securities with maturities of 90 days or less at the date of purchase. The remaining maturities of our long-term marketable securities range from one to three years and our short-term marketable securities include maturities that were greater than 90 days at the date purchased and have 12 months or less remaining at March 31, 2018 and December 31, 2017, respectively. For assets and liabilities required to be reported at fair value, GAAP provides a hierarchy that prioritizes inputs to valuation techniques used to measure fair value into three broad levels: Level 1—Valuations are based on quoted market prices for identical assets and liabilities in active markets. Level 2—Valuations are based on observable inputs other than quoted market prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. Level 3—Valuations are based on unobservable inputs reflecting our own assumptions, consistent with reasonably available assumptions made by other market participants. These valuations require significant judgment. We classify our cash, cash equivalents, restricted cash and marketable securities within Level 1 and Level 2 as we value these financial instruments using quoted market prices (Level 1) or alternative pricing sources (Level 2). The valuation technique we used to measure the fair value of money market funds was derived from quoted prices in active markets for identical assets or liabilities. Fair values for Level 2 marketable securities are considered “Level 2” valuations because they are obtained from independent pricing sources for identical or comparable instruments, rather than direct observations of quoted prices in active markets. Our procedures include controls to ensure that appropriate fair values are recorded, including comparing the fair values obtained from our independent pricing services against fair values obtained from another independent source. There were no material realized gains or losses related to sales of our marketable securities for the three months ended March 31, 2018 and 2017. Realized gains and losses on the sale of securities are determined by specific identification of each security’s cost basis. We consider any unrealized loss position in our available-for-sale marketable debt securities to be temporary in nature and do not consider any of these investments other-than-temporarily impaired as of March 31, 2018. Derivative Financial Instruments Derivative financial instruments are carried at fair value on our unaudited condensed consolidated balance sheets. We use foreign currency forward contracts to reduce the effects of foreign currency exchange rate fluctuations on our cash flows primarily for the Euro versus the U.S. Dollar. Our foreign currency forward contracts, which we have entered into to date, have not been designated as hedges and have had current maturities of less than 90 days. Any gain or loss resulting from the change in fair value of the foreign currency forward contracts was recognized in our unaudited condensed consolidated statement of operations in interest income and other, net, and was not material for the three months ended March 31, 2018 and 2017. The Company did not have any outstanding foreign currency derivatives as of March 31, 2018 and December 31, 2017. Other Financial Instruments Other financial instruments not measured at fair value on a recurring basis include accounts receivable and contract assets, accounts payable, deferred merchant payables, short-term debt, accrued and other current liabilities and long-term debt. The carrying amount of these financial instruments, with the exception of long-term debt, approximate their fair value because of the short maturity of these instruments as reported on our unaudited condensed consolidated balance sheets as of March 31, 2018 and December 31, 2017. The carrying value of the long-term debt from our 2015 Credit Facility bears interest at a variable rate and therefore is also considered to approximate its fair value. In addition, we also hold investments in equity securities of privately-held companies that do not have a readily determinable fair value. As of both March 31, 2018 and December 31, 2017, the total carrying value of our equity investments in these privately-held companies were $12 million and are included in other long-term assets on our unaudited condensed consolidated balance sheet. Our policy is to measure these investments at cost less impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. On a quarterly basis, we perform a qualitative assessment considering impairment indicators to evaluate whether these investments are impaired and also monitor for any observable price changes. During the three months ended March 31, 2018 and 2017, we did not have any impairment loss on these equity investments. The Company did not have assets or liabilities measured at fair value on a recurring basis using the Level 3 unobservable inputs at both March 31, 2018 and December 31, 2017.

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	NOTE 7: DEBT The Company’s outstanding debt consisted of the following as of the dates presented: March 31, December 31, 2018 2017 (in millions) Short-Term Debt: Chinese Credit Facilities $ 7 $ 7 Total Short-Term Debt (1) $ 7 $ 7 Long-Term Debt: 2015 Credit Facility $ — $ 230 Total Long-Term Debt $ — $ 230 2015 Credit Facility We are party to a five year credit agreement with a group of lenders which, among other things, provides for a $1.2 billion unsecured revolving credit facility (the “2015 Credit Facility”) with a maturity date of May 12, 2022. Borrowings under the 2015 Credit Facility generally bear interest, at the Company’s option, at a rate per annum equal to either (i) the Eurocurrency Borrowing rate, or the adjusted LIBO rate for the interest period in effect for such borrowing; plus an applicable margin ranging from 1.25% to 2.00% (“Eurocurrency Spread”), based on the Company’s leverage ratio; or (ii) the Alternate Base Rate (“ABR”) Borrowing, which is the greatest of (a) the Prime Rate in effect on such day, (b) the New York Fed Bank Rate in effect on such day plus 1/2 of 1.00% per annum and (c) the Adjusted LIBO Rate (or LIBO rate multiplied by the Statutory Reserve Rate) for an interest period of one month plus 1.00%; in addition to an applicable margin ranging from 0.25% to 1.00% (“ABR Spread”), based on the Company’s leverage ratio. The Company may borrow from the 2015 Credit Facility in U.S. dollars, Euros and British pound sterling. During the three months ended March 31, 2018, the Company borrowed an additional $5 million and repaid $235 million of our outstanding borrowings on the 2015 Credit Facility. These net repayments were primarily made from a one-time cash repatriation of $325 million of foreign earnings to the United States during the first quarter of 2018. As of March 31, 2018, there were no outstanding borrowings under the 2015 Credit Facility. We are required to pay a quarterly commitment fee, at an applicable rate ranging from 0.15% to 0.30%, on the daily unused portion of the revolving credit facility for each fiscal quarter and additional fees in connection with the issuance of letters of credit. As of March 31, 2018, our unused revolver capacity was subject to a commitment fee of 0.15%, given the Company’s leverage ratio. The 2015 Credit Facility includes $15 million of borrowing capacity available for letters of credit and $40 million for Swing Line borrowings on same-day notice. As of March 31, 2018, we had issued $3 million of outstanding letters of credit under the 2015 Credit Facility. We recorded total interest expense and commitment fees on our 2015 Credit Facility of $1 million for both the three months ended March 31, 2018 and 2017 to interest expense on our unaudited condensed consolidated statements of operations. All unpaid interest and commitment fee amounts as of March 31, 2018 and December 31, 2017, respectively, were not material. There is no specific repayment date prior to the maturity date for borrowings under this credit agreement. We may voluntarily repay any outstanding borrowing under the 2015 Credit Facility at any time without premium or penalty, other than customary breakage costs with respect to Eurocurrency loans. Additionally, the Company believes that the likelihood of the lender exercising any subjective acceleration rights, which would permit the lenders to accelerate repayment of any outstanding borrowings, is remote. As such, we classify any borrowings under this facility as long-term debt. The 2015 Credit Facility contains a number of covenants that, among other things, restrict our ability to: incur additional indebtedness, create liens, enter into sale and leaseback transactions, engage in mergers or consolidations, sell or transfer assets, pay dividends and distributions, make investments, loans or advances, prepay certain subordinated indebtedness, make certain acquisitions, engage in certain transactions with affiliates, amend material agreements governing certain subordinated indebtedness, and change our fiscal year. The 2015 Credit Facility also requires us to maintain a maximum leverage ratio and contains certain customary affirmative covenants and events of default, including a change of control. If an event of default occurs, the lenders under the 2015 Credit Facility will be entitled to take various actions, including the acceleration of all amounts due under the 2015 Credit Facility. As of March 31, 2018, we were in compliance with all of our debt covenants. 2016 Credit Facility We are party to an uncommitted facility agreement which provides for a $73 million unsecured revolving credit facility (the “2016 Credit Facility”) with no specific expiration date. The 2016 Credit Facility is available at the lender’s discretion and can be canceled at any time. Repayment terms for borrowings under the 2016 Credit Facility are generally one to six month periods or such other periods as the parties may mutually agree and bear interest at LIBO rate plus 112.5 basis points. The Company may borrow from the 2016 Credit Facility in U.S. dollars only and we may voluntarily repay any outstanding borrowing at any time without premium or penalty. There are no specific financial or incurrence covenants. The Company repaid outstanding borrowings of $73 million during the three months ended March 31, 2017. As of March 31, 2018 and December 31, 2017, there were no outstanding borrowings under the 2016 Credit Facility. During the three months ended March 31, 2017, total interest recorded with respect to our 2016 Credit Facility to interest expense on our unaudited condensed consolidated statement of operations was not material. Chinese Credit Facilities In addition to our 2015 Credit Facility and 2016 Credit Facility, we maintain two credit facilities in China (jointly, the “Chinese Credit Facilities”). We are party to a $30 million, one-year revolving credit facility with Bank of America (the “Chinese Credit Facility—BOA”) that is currently subject to review on a periodic basis with no specific expiration period. Borrowings under our Chinese Credit Facility – BOA generally bear interest at a rate based on People’s Bank of China benchmark, including certain adjustments which may be made in accordance with market conditions at the time of borrowing. As of March 31, 2018 and December 31, 2017, there were no outstanding borrowings under our Chinese Credit Facility—BOA. We are also party to a RMB 70,000,000 (approximately $11 million) one-year revolving credit facility with J.P. Morgan Chase Bank (“Chinese Credit Facility-JPM”). Our Chinese Credit Facility—JPM generally bears interest at a rate based on People’s Bank of China benchmark, including certain adjustments which may be made in accordance with market conditions at the time of borrowing. As of both March 31, 2018 and December 31, 2017, we had $7 million of outstanding borrowings from the Chinese Credit Facility – JPM at a weighted average rate of 4.98% and 5.00%, respectively.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 8: INCOME TAXES Each interim period is considered an integral part of the annual period and, accordingly, we measure our income tax expense using an estimated annual effective tax rate. An enterprise is required, at the end of each interim reporting period, to make its best estimate of the annual effective tax rate for the full fiscal year and use that rate to provide for income taxes on a current year-to-date basis, as adjusted for discrete taxable events that occur during the interim period. Our effective tax rate for the three months ended March 31, 2018 and 2017 was 76.2% and 48.0%, respectively. For the three months ended March 31, 2018, the effective tax rate was greater than the federal statutory rate primarily due to international provisions from the U.S. Tax Cuts and Jobs Act of 2017 (“2017 Tax Act”), discussed below, foreign valuation allowances, and the income tax effects of the accounting for share based compensation. The change in the effective tax rate for the three months ended March 31, 2018 compared to the three months ended March 31, 2017 rate was primarily due to the Transition Tax, discussed below, and a lower stock price resulting in stock compensation shortfalls. The 2017 Tax Act introduced significant changes to U.S. income tax law. Changes include, but are not limited to, a corporate tax rate decrease from 35% to 21% effective for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system, and a one-time tax on the mandatory deemed repatriation of cumulative foreign earnings (the “Transition Tax”) as of December 31, 2017. On December 22, 2017, the SEC issued Staff Accounting Bulletin No. 118, or SAB 118, which allows us to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. The measurement period is deemed to have ended earlier when the registrant has obtained, prepared, and analyzed the information necessary to finalize its accounting. During the measurement period, impacts of the law are expected to be recorded at the time a reasonable estimate for all or a portion of the effects can be made, and provisional amounts can be recognized and adjusted as information becomes available, prepared, or analyzed. During the quarter ended March 31, 2018, we recorded an incremental $5 million tax expense for the Transition Tax, which we initially recorded in the quarter ended December 31, 2017, reflecting additional information obtained relating to earnings and profits, foreign tax credits, and state taxes. Additional work is still necessary for a more detailed analysis of our historical foreign earnings. Any subsequent adjustment to these amounts will be recorded to current tax expense in the quarter of 2018 when the analysis is complete. We are subject to additional requirements of the 2017 Tax Act during the year ended December 31, 2018. Those provisions include a tax on global intangible low-taxed income (“GILTI”), a limitation of certain executive compensation, and a deduction for foreign derived intangible income (“FDII”). We have elected to account for GILTI as a period cost, and therefore included GILTI expense in the effective tax rate calculation. Our 2018 effective tax rate includes our estimates of these new provisions, with a net tax benefit of $1 million recorded in Q1. Our estimates may be revised in future periods as we obtain additional data, and as the Internal Revenue Service (“IRS”) issues new guidance implementing the law changes. Our policy is to recognize accrued interest and penalties related to unrecognized tax benefits and income tax liabilities as part of our income tax expense. As of March 31, 2018, accrued interest was $11 million, net of federal and state benefit, and no penalties have been accrued. By virtue of consolidated income tax returns previously filed with Expedia, we are currently under an IRS audit for the 2009, 2010 and short-period 2011 tax years, and have various ongoing state income tax audits. We are separately under examination by the IRS for the short-period 2011, 2012 and 2013 tax years and under an employment tax audit by the IRS for the 2013 and 2014 tax years. These audits include questioning of the timing and the amount of income and deductions and the allocation of income among various tax jurisdictions. These examinations may lead to proposed or ordinary course adjustments to our taxes. We are no longer subject to tax examinations by tax authorities for years prior to 2009. As of March 31, 2018, no material assessments have resulted, except as noted below regarding our 2009 and 2010 IRS audit with Expedia . In January 2017, as part of the IRS audit of Expedia, we received Notices of Proposed Adjustment from the IRS for the 2009 and 2010 tax years. These proposed adjustments are related to certain transfer pricing arrangements with our foreign subsidiaries, and would result in an increase to our worldwide income tax expense in an estimated range of $10 million to $14 million after consideration of competent authority relief, exclusive of interest and penalties. We disagree with the proposed adjustments and we intend to defend our position through applicable administrative and, if necessary, judicial remedies. Our policy is to review and update tax reserves as facts and circumstances change. Based on our interpretation of the regulations and available case law, we believe the position we have taken with regard to transfer pricing with our foreign subsidiaries is sustainable. In addition to the risk of additional tax for 2009 and 2010 transactions, if the IRS were to seek transfer pricing adjustments of a similar nature for transactions in subsequent years, we would be subject to significant additional tax liabilities. In July 2015, the United States Tax Court (the “Court”) issued an opinion favorable to Altera Corporation (“Altera”) with respect to Altera’s litigation with the IRS. This opinion was submitted as a final decision under Tax Court Rule 155 during December 2015. The litigation relates to the treatment of stock-based compensation expense in an inter-company cost-sharing arrangement with Altera’s foreign subsidiary. In its opinion, the Court accepted Altera’s position of excluding stock based compensation from its inter-company cost-sharing arrangement. The IRS appealed the Court decision on February 19, 2016. At this time, the U.S. Department of the Treasury has not withdrawn the requirement from its regulations to include stock-based compensation in intercompany cost-sharing arrangements. The Company recorded a tax benefit of $1 million in its unaudited condensed consolidated statement of operations for both the three months ended March 31, 2018 and 2017. The Company will continue to monitor this matter and related potential impacts to its consolidated financial statements

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 9: COMMITMENTS AND CONTINGENCIES There have been no material changes to our commitments and contingencies since December 31, 2017. Refer to “Note 13: Commitments and Contingencies Legal Proceedings In the ordinary course of business, we are parties to regulatory and legal matters arising out of our operations. These matters may involve claims involving alleged infringement of third-party intellectual property rights (including patent infringement), defamation, taxes, regulatory compliance, privacy issues and other claims. Periodically, we review the status of all significant outstanding matters to assess any potential financial exposure. When (i) it is probable that an asset has been impaired or a liability has been incurred; and (ii) the amount of the loss can be reasonably estimated, we record the estimated loss in our consolidated statements of operations. We provide disclosures in the notes to the consolidated financial statements for loss contingencies that do not meet both of these conditions if there is a reasonable probability that a loss may have been incurred and whether such loss is reasonably estimable. We base accruals made on the best information available at the time which can be highly subjective. Although occasional adverse decisions or settlements may occur, the Company does not believe that the final disposition of any of these matters will have a material adverse effect on the business. However, the final outcome of these matters could vary significantly from our estimates. Finally, there may be claims or actions pending or threatened against us of which we are currently not aware and the ultimate disposition of which could have a material adverse effect on us. Income Taxes We are also under audit by the IRS and various other domestic and foreign tax authorities with regards to income tax matters. We have reserved for potential adjustments to our provision for income taxes that may result from examinations by, or any negotiated agreements with, these tax authorities. Although we believe our tax estimates are reasonable, the final determination of audits could be materially different from our historical income tax provisions and accruals. The results of an audit could have a material effect on our financial position, results of operations, or cash flows in the period for which that determination is made. We continue to accumulate cash flows, in foreign jurisdictions which we consider indefinitely reinvested, although we will continue to evaluate the impact of the 2017 Tax Act on our capital deployment within and outside the U.S. Any repatriation of funds currently held in foreign jurisdictions may result in withholding taxes and state taxes. Refer to “Note 8: Income Taxes

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Stockholders' Equity	NOTE 10: STOCKHOLDERS’ EQUITY On January 31, 2018, our Board of Directors authorized up to $250 million of share repurchases. Our Board of Directors authorized and directed management, working with the Executive Committee of our Board of Directors, to affect the share repurchase program in compliance with applicable legal requirements. This repurchase program has no expiration date but may be suspended or terminated by the Board of Directors at any time. During the three months ended March 31, 2018, we repurchased 252,650 shares of outstanding common stock under the share repurchase program at an aggregate cost of $10 million, or an average share price of $39.88, of which $6 million remains payable and is recorded in accrued expenses and other current liabilities on our unaudited condensed consolidated balance sheet at March 31, 2018. As of March 31, 2018, we had a remaining balance of $240 million available to repurchase shares of our common stock under the share repurchase program. Subsequent to March 31, 2018, we repurchased an additional 2,329,548 shares for an aggregate cost of $90 million, or an average price of $38.60 per share. As of May 7, 2018, we had a remaining balance of $150 million available to repurchase shares of our common stock under the share repurchase program.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	NOTE 11: RELATED PARTY TRANSACTIONS We consider Liberty TripAdvisor Holdings, Inc. (“LTRIP”) a related party. As of March 31, 2018, LTRIP beneficially owned approximately 18.2 million shares of our common stock and 12.8 million shares of our Class B common stock, which shares constitute 14.3% of the outstanding shares of common stock and 100% of the outstanding shares of Class B common stock. Assuming the conversion of all of LTRIP’s shares of Class B common stock into common stock, LTRIP would beneficially own 22.2% of the outstanding common stock. Because each share of Class B common stock generally is entitled to ten votes per share and each share of common stock is entitled to one vote per share, LTRIP may be deemed to beneficially own equity securities representing 57.4% of our voting power. We had no related party transactions with LTRIP during both the three months ended March 31, 2018 and 2017.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Information	NOTE 12: SEGMENT INFORMATION Our reporting structure includes two reportable segments: Hotel and Non-Hotel. Our Non-Hotel segment consists of the aggregation of three operating segments: Experiences, Restaurants and Rentals. The nature of the services provided are summarized in “Note 3: Revenue Recognition Our operating segments are determined based on how our chief operating decision maker manages our business, regularly assesses information and evaluates performance for operating decision-making purposes, including allocation of resources. The chief operating decision maker for the Company is our CEO. Adjusted EBITDA is our segment profit measure and a key measure used by our management and board of directors to understand and evaluate the operating performance of our business and on which internal budgets and forecasts are based and approved. In particular, the exclusion of certain expenses in calculating Adjusted EBITDA can provide a useful measure for period-to-period comparisons of our core business. The following tables present our segment information for the three months ended March 31, 2018 and 2017 and include a reconciliation of Adjusted EBITDA to Net Income. We record depreciation of property and equipment, including amortization of internal-use software and website development, amortization of intangible assets, stock-based compensation and other stock-settled obligations, other income (expense), net, other non-recurring expenses and income, net, and income taxes, which are excluded from segment operating performance, in corporate and unallocated. In addition, we do not report our assets, capital expenditures and related depreciation expense by segment as our chief operating decision maker does not use this information to evaluate operating segments. Accordingly, we do not regularly provide such information by segment to our chief operating decision maker. Intersegment revenue is not material and, in addition, already eliminated in the information by segment provided to our chief operating decision maker. Our consolidated general and administrative expenses, excluding stock-based compensation costs, are shared by all operating segments. Each operating segment receives an allocated charge based on the segment’s percentage of the Company’s total personnel costs. Three months ended March 31, 2018 Hotel Non-Hotel Corporate and Unallocated Total (in millions) Revenue $ 299 $ 79 $ - $ 378 Adjusted EBITDA (1) 88 (8 ) - 80 Depreciation (20 ) (20 ) Amortization of intangible assets (8 ) (8 ) Stock-based compensation (29 ) (29 ) Operating income 23 Other expense, net (2 ) Income before income taxes 21 Provision for income taxes (16 ) Net income 5 Three months ended March 31, 2017 Hotel Non-Hotel Corporate and Unallocated Total (in millions) Revenue $ 314 $ 58 $ - $ 372 Adjusted EBITDA (1) 88 (15 ) - 73 Depreciation (19 ) (19 ) Amortization of intangible assets (8 ) (8 ) Stock-based compensation (19 ) (19 ) Operating income 27 Other expense, net (2 ) Income before income taxes 25 Provision for income taxes (12 ) Net income 13 (1) Includes allocated general and administrative expenses in our Hotel segment of $20 million and $19 million; and in our Non-Hotel segment of $12 million and $9 million for the three months ended March 31, 2018 and 2017, respectively.

Significant Accounting Polici21

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements present our results of operations, financial position and cash flows on a consolidated basis. The unaudited condensed consolidated financial statements include TripAdvisor, our wholly-owned subsidiaries, and entities we control, or in which we have a variable interest and are the primary beneficiary of expected cash profits or losses. All inter-company accounts and transactions have been eliminated in consolidation. One of our subsidiaries that operates in China has variable interests in affiliated entities in China in order to comply with Chinese laws and regulations, which restrict foreign investment in Internet content provision businesses. Although we do not own the capital stock of these Chinese affiliates, we consolidate their results as we are the primary beneficiary of the cash losses or profits of these variable interest affiliates and have the power to direct the activity of these affiliates. Our variable interest entities’ financials were not material for all periods presented. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and include all normal and recurring adjustments that management of the Company considers necessary for a fair presentation of its financial position and operating results.
Accounting Estimates	Accounting Estimates We use estimates and assumptions in the preparation of our unaudited condensed consolidated financial statements in accordance with GAAP. Our estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of our unaudited condensed consolidated financial statements. These estimates and assumptions also affect the reported amount of net income or loss during any period. Our actual financial results could differ significantly from these estimates. The significant estimates underlying our unaudited condensed consolidated financial statements include: (i) recognition and recoverability of goodwill, definite-lived intangibles and other long-lived assets; and (ii) accounting for income taxes.
Seasonality	Seasonality Traveler expenditures in the global travel market tend to follow a seasonal pattern. As such, expenditures by travel partners/advertisers to market to potential travelers and, therefore our financial performance, or revenue and profits, tend to be seasonal as well. Our financial performance tends to be seasonally highest in the second and third quarters of a year, as it is a key period for leisure travel research and trip-taking, which includes the seasonal peak in traveler hotel and rental stays, and tours and experiences taken, compared to the first and fourth quarters which represent seasonal low points. Further significant shifts in our business mix or adverse economic conditions could result in future seasonal patterns that are different from historical trends.
New Accounting Pronouncements Not Yet Adopted and Recently Adopted Accounting Pronouncements	New Accounting Pronouncements Not Yet Adopted In June 2016, the Financial Accounting Standard Board (“FASB”) issued new accounting guidance on the measurement of credit losses for financial assets measured at amortized cost, which includes accounts receivable, and available-for-sale debt securities. For financial assets measured at amortized cost, this new guidance requires an entity to: (1) estimate its lifetime expected credit losses upon recognition of the financial assets and establish an allowance to present the net amount expected to be collected; (2) recognize this allowance and changes in the allowance during subsequent periods through net income; and (3) consider relevant information about past events, current conditions and reasonable and supportable forecasts in assessing the lifetime expected credit losses. For available-for-sale debt securities, this new guidance made several targeted amendments to the existing other-than-temporary impairment model, including: (1) requiring disclosure of the allowance for credit losses; (2) allowing reversals of the previously recognized credit losses until the entity has the intent to sell, is more-likely-than-not required to sell the securities or the maturity of the securities; (3) limiting impairment to the difference between the amortized cost basis and fair value; and (4) not allowing entities to consider the length of time that fair value has been less than amortized cost as a factor in evaluating whether a credit loss exists. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted, including interim periods within those fiscal years beginning after December 15, 2018. We are currently considering our timing of adoption and in the process of evaluating the impact of adopting this guidance on our consolidated financial statements and related disclosures. In February 2016, the FASB issued new guidance related to accounting for leases. The new standard requires the recognition of assets (right-of-use-assets) and liabilities arising from lease transactions on the balance sheet and the disclosure of key information about leasing arrangements. Accordingly, a lessee will recognize a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. Both the asset and liability will initially be measured at the present value of the future minimum lease payments over the lease term. The new guidance will classify leases as either finance or operating leases, with classification determining the presentation of expenses and cash flows on our consolidated financial statements. Initial costs directly attributable to negotiating and arranging the lease will be included in the asset. We continue to evaluate the new lease guidance and are in the process of updating accounting policies, accounting position memos, and evaluating our existing population of contracts to ensure all contracts that meet the definition of a lease contract under the new standard are identified. We are also in the process of implementing additional lease software to support our accounting and reporting process, including the new quantitative and qualitative financial disclosure requirements. In addition, we are evaluating the impact of the system implementation and new accounting guidance on our internal controls. We will continue to provide updates on our assessment of the effect that this new lease guidance will have on our consolidated financial statements, disclosures, systems and related internal controls, and will disclose material effects, if any, when known. Recently Adopted Accounting Pronouncements In May 2017, the FASB issued new accounting guidance that clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications which will reduce diversity in practice. Under the new guidance, an entity will not apply modification accounting to a share-based payment award if the award’s fair value (or calculated value or intrinsic value, if those measurement methods are used), the award’s vesting conditions, and the award’s classification as an equity or liability instrument are the same immediately before and after the change. The guidance also states that an entity is not required to estimate the value of the award immediately before and after the change if the change does not affect any of the inputs to the model used to value the award. We adopted this guidance prospectively in the first quarter of 2018. We believe the new guidance will likely result in fewer changes to the terms of an award being accounted for as modifications. In January 2017, the FASB issued new accounting guidance to clarify the definition of a business and provide additional guidance to assist entities with evaluating whether transactions should be accounted for as asset acquisitions (or asset disposals) or business combinations (or disposals of a business). Under this new guidance, an entity first determines whether substantially all of the fair value of the assets acquired is concentrated in a single identifiable asset or a group of similar identifiable assets. If this criterion is met, the transaction should be accounted for as an asset acquisition as opposed to a business combination. This distinction is important because the accounting for an asset acquisition significantly differs from the accounting for a business combination. This new guidance eliminates the requirement to evaluate whether a market participant could replace missing elements (e.g. inputs or processes), narrows the definition of outputs and requires that a business include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create outputs. We adopted this guidance in the first quarter of 2018 and it will be applied prospectively to any transactions occurring within and after the adoption date. In November 2016, the FASB issued new accounting guidance on the classification and presentation of restricted cash in the statement of cash flows to address the diversity in practice. This new guidance requires entities to show changes in cash, cash equivalents and restricted cash on a combined basis in the statement of cash flows. In addition, this accounting guidance requires a reconciliation of the total cash, cash equivalent and restricted cash in the statement of cash flows to the related captions in the balance sheet if cash, cash equivalents and restricted cash are presented in more than one line item in the balance sheet. We adopted this guidance in the first quarter of 2018 and applied it retrospectively to all prior periods presented in the financial statements as required under the new guidance. The adoption did not have a material impact on our consolidated financial statements and related disclosures. In October 2016, the FASB issued new accounting guidance on income tax accounting associated with intra-entity transfers of assets other than inventory. This accounting update, which is part of the FASB's simplification initiative, is intended to reduce diversity in practice and the complexity of tax accounting, particularly for those transfers involving intellectual property. This new guidance requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. We adopted this new guidance in the first quarter of 2018 on a modified retrospective basis. Accordingly, we recognized the cumulative effect of initial application of this new guidance as an adjustment to the opening balance of retained earnings, which was not material to our consolidated financial statements. In August 2016, the FASB issued new accounting guidance which clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. The new guidance specifically addresses the following cash flow topics in an effort to reduce diversity in practice: (1) debt prepayment or debt extinguishment costs; (2) settlement of zero-coupon bonds; (3) contingent consideration payments made after a business combination; (4) proceeds from the settlement of insurance claims; (5) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; (6) distributions received from equity method investees; (7) beneficial interests in securitization transactions; and (8) separately identifiable cash flows and application of the predominance principle. We adopted this new guidance in the first quarter of 2018 retrospectively and the adoption did not have an impact on our consolidated financial statements and related disclosures. In January 2016, the FASB issued new accounting guidance which amends the standard on the recognition and measurement of financial instruments. The FASB clarified certain aspects of this guidance by issuing an update for technical corrections and improvements related to this guidance in February 2018. The guidance (1) requires an entity to measure equity investments (except those accounted for under the equity method or those that result in consolidation of the investee) at fair value with changes in fair value recognized in net income rather than accumulated other comprehensive income on the balance sheet; (2) allows an entity to elect to measure the equity investments that do not have a readily determinable fair value using a new measurement alternative which measure these equity investments at cost less impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer; (3) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; and (4) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s evaluation of their other deferred tax assets. We adopted this guidance in the first quarter of 2018 and elected to prospectively account for our investments in equity securities of privately-held companies that do not have a readily determinable fair value using In May 2014, the FASB issued new accounting guidance on revenue from contracts with customers, or ASC 606, Revenue from Contracts with Customers In the first quarter of 2018, we adopted ASC 606 under the modified retrospective method for all contracts that were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under the new revenue guidance, while prior period amounts are not adjusted and continue to be reported in accordance with our previous accounting policies under the historical revenue guidance, or ASC 605, Revenue Recognition We evaluated each of our revenue streams and applied ASC 606 as further discussed in “Note 3: Revenue Recognition We recognized the cumulative effect of initial application of ASC 606 as an adjustment to the opening balance of retained earnings. We recorded a net increase in opening retained earnings of $4 million as of January 1, 2018 due to the cumulative impact of adoption of the new revenue guidance and all other accounts were not materially impacted. There have been no changes to our significant accounting policies since December 31, 2017, other than noted above. See “Note 3: Revenue Recognition Significant Accounting Policies

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2018
Reconciliation of Disaggregated Revenue to Segment Revenue	A reconciliation of disaggregated revenue to segment revenue is also included below. Three months ended March 31, 2018 Major products/revenue sources: (in millions) Click-based advertising and transaction revenue $ 189 Display-based advertising and subscription revenue 71 Other hotel revenue 39 Total Hotel Revenue (1) 299 Non-Hotel Revenue (1) 79 Total Revenue $ 378 (1) Our revenue is recognized primarily at a point in time for both our Hotel and Non-Hotel segments.
Summary of Balances of Accounts Receivables and Contract Assets from Contracts with Customers	The following table provides information about the opening and closing balances of accounts receivables and contract assets from contracts with customers (in millions): March 31, 2018 December 31, 2017 Accounts receivable $ 269 $ 230 Contract assets 12 - Total $ 281 $ 230
ASC 606
Summary of Impact of New Revenue Recognition Guidance on Unaudited Condensed Consolidated Statement of Operations	The impact of this new revenue recognition guidance on our unaudited condensed consolidated statement of operations for the three months ended March 31, 2018 was as follows: As Reported - ASC 606 March 31, 2018 Impact of Accounting under ASC 606 Adjusted - ASC 605 March 31, 2018 (in millions) Revenue $ 378 $ (4 ) $ 374 Operating income 23 (4 ) 19 Income before income taxes 21 (4 ) 17 Provision for income taxes (16 ) 1 (15 ) Net income 5 (3 ) 2

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Reconciliation of Weighted Average Number of Shares of Common Stock Outstanding	Below is a reconciliation of the weighted average number of shares of common stock outstanding in calculating Diluted EPS (shares in thousands and dollars in millions, except per share amounts) for the periods presented: Three months ended March 31, 2018 2017 Numerator: Net income $ 5 $ 13 Denominator: Weighted average shares used to compute Basic EPS 139,312 143,632 Weighted average effect of dilutive securities: Stock options 118 516 RSUs/MSUs 892 569 Weighted average shares used to compute Diluted EPS 140,322 144,717 Basic EPS $ 0.04 $ 0.09 Diluted EPS $ 0.04 $ 0.09

Stock Based Awards and Other 24

Stock Based Awards and Other Equity Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Summary of RSU Activity, Including Service Based Awards and Performance-Based Awards	Weighted Average Grant- Aggregate RSUs Date Fair Intrinsic Outstanding Value Per Share Value (in thousands) (in millions) Unvested RSUs outstanding as of December 31, 2017 (1) 6,015 $ 48.14 Transfer (1) (213 ) 30.04 Granted 2,590 41.44 Vested and released (2) (1,007 ) 56.11 Cancelled (160 ) 47.26 Unvested RSUs outstanding as of March 31, 2018 7,225 $ 45.18 $ 295 Expected to vest after March 31, 2018 (3) 7,225 $ 45.18 $ 295 (1) RSUs outstanding as of December 31, 2017 include 213,000 MSUs awarded to the Company’s CEO in November 2017. This award has been transferred to the MSU activity table below. (2) Inclusive of 269,878 RSUs withheld due to net share settlement to satisfy required employee tax withholding requirements. Potential shares which had been convertible under RSUs that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the unaudited condensed consolidated statements of cash flows. (3) The Company accounts for forfeitures as they occur, rather than estimate expected forfeitures as allowed under GAAP and therefore do not include a forfeiture rate in our expected to vest calculation unless necessary for a performance condition award.
Amount of Stock-Based Compensation Expense Related to Stock-Based Awards, Primarily Stock Options and RSUs	The following table presents the amount of stock-based compensation expense related to stock-based awards, primarily stock options and RSUs, on our unaudited condensed consolidated statements of operations during the periods presented: Three months ended March 31, 2018 2017 (in millions) Selling and marketing $ 6 $ 5 Technology and content 12 7 General and administrative 11 7 Total stock-based compensation 29 19 Income tax benefit from stock-based compensation (7 ) (7 ) Total stock-based compensation, net of tax effect $ 22 $ 12
Summary of Stock Option Activity	A summary of our stock option activity during the three months ended March 31, 2018, is presented below: Weighted Weighted Average Average Exercise Remaining Aggregate Options Price Per Contractual Intrinsic Outstanding Share Life Value (in thousands) (in years) (in millions) Options outstanding at December 31, 2017 6,853 $ 52.78 Granted 611 41.54 Exercised (1) (196 ) 28.21 Cancelled or expired (72 ) 47.80 Options outstanding at March 31, 2018 7,196 $ 52.48 6.7 $ 10 Exercisable as of March 31, 2018 3,428 $ 54.81 4.7 $ 5 Vested and expected to vest after March 31, 2018 (2) 7,196 $ 52.48 6.7 $ 10 (1) Inclusive of 150,855 of options which were not converted into shares due to net share settlement in order to cover the aggregate exercise price and the required amount of employee withholding taxes. Potential shares that had been convertible under stock options that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the unaudited condensed consolidated statements of cash flows. (2) The Company accounts for forfeitures as they occur, rather than estimate expected forfeitures as allowed under GAAP and therefore do not include a forfeiture rate in our vested and expected to vest calculation unless necessary for a performance condition award.
Weighted-Average Assumptions of Estimated Fair Value of Stock Option Grants	The fair value of stock option grants under the 2011 Incentive Plan has been estimated at the date of grant using the Black–Scholes option pricing model with the following weighted average assumptions for the periods presented: Three months ended March 31, 2018 2017 Risk free interest rate 2.66 % 1.91 % Expected term (in years) 5.45 5.35 Expected volatility 42.29 % 41.53 % Expected dividend yield — % — %
Summary of Unrecognized Stock-Based Compensation Expense and Weighted Average Period Remaining	A summary of our remaining unrecognized stock-based compensation expense and the weighted average remaining amortization period at March 31, 2018 related to our non-vested equity awards is presented below (in millions, except in years information): Stock Options RSUs MSUs Unrecognized compensation expense $ 55 $ 302 $ 10 Weighted average period remaining (in years) 3.0 3.2 2.8
MSUs
Summary of RSU Activity, Including Service Based Awards and Performance-Based Awards	A summary of our RSU activity for MSUs, during the three months ended March 31, 2018 is presented below: Weighted Average Grant- Aggregate MSUs Date Fair Intrinsic Outstanding Value Per Share Value (in thousands) (in millions) Unvested MSUs outstanding as of December 31, 2017 (1) 213 $ 30.04 Granted (2) 71 59.40 Vested and released ― ― Cancelled ― ― Unvested MSUs outstanding as of March 31, 2018 284 $ 37.41 $ 12 (1) (2) MSUs provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2018 through December 31, 2020 relative to the TSR performance of the Nasdaq Composite Total Return Index. A Monte-Carlo simulation model, which simulated the present value of the potential outcomes of future stock prices and TSR of the Company and the Nasdaq Composite Total Return Index over the performance period, was used to calculate the grant-date fair value of these awards. The estimated grant-date fair value of these awards is being amortized on a straight-line basis over the requisite service period through December 31, 2020. Based upon actual attainment relative to the target performance metric, the grantee has the ability to receive up to 200% of the target number of MSUs originally granted, or to be issued none at all. These MSUs were granted under the 2011 Incentive Plan.

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Investments All Other Investments [Abstract]
Schedule of Cash, Cash Equivalents, Restricted Cash and Marketable Securities	The following tables show our cash, cash equivalents, restricted cash and short-term and long-term available-for-sale marketable debt securities, by major security type, that are measured at fair value on a recurring basis and were categorized using the fair value hierarchy, as well as their classification on March 31, 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash, Cash Equivalents and Restricted Cash Short-Term Marketable Securities Long-Term Marketable Securities Cash and restricted cash (1) $ 340 $ — $ — $ 340 $ 340 $ — $ — Level 1: Money market funds 295 — — 295 295 — — Level 2: U.S. agency securities 4 — — 4 — 4 — Certificates of deposit 2 — — 2 — 2 — Corporate debt securities 14 — — 14 — 9 5 Subtotal 20 — — 20 — 15 5 Total $ 655 — — $ 655 $ 635 $ 15 $ 5 December 31, 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash, Cash Equivalents and Restricted Cash Short-Term Marketable Securities Long-Term Marketable Securities Cash and restricted cash (1) $ 663 $ — $ — $ 663 $ 663 $ — $ — Level 1: Money market funds 1 — — 1 1 — — Level 2: U.S. agency securities 11 — — 11 — 6 5 U.S. treasury securities 1 — — 1 — 1 — Certificates of deposit 2 — — 2 — 2 — Commercial paper 11 — — 11 9 2 — Corporate debt securities 46 — — 46 — 24 22 Subtotal 71 — — 71 9 35 27 Total $ 735 — — $ 735 $ 673 35 27 (1) As of March 31, 2018 and December 31, 2017, our restricted cash which primarily consists of escrowed security deposits, was not material and is included in other long-term assets on our unaudited condensed consolidated balance sheets.

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	The Company’s outstanding debt consisted of the following as of the dates presented: March 31, December 31, 2018 2017 (in millions) Short-Term Debt: Chinese Credit Facilities $ 7 $ 7 Total Short-Term Debt (1) $ 7 $ 7 Long-Term Debt: 2015 Credit Facility $ — $ 230 Total Long-Term Debt $ — $ 230

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Summary of Segment Information	Three months ended March 31, 2018 Hotel Non-Hotel Corporate and Unallocated Total (in millions) Revenue $ 299 $ 79 $ - $ 378 Adjusted EBITDA (1) 88 (8 ) - 80 Depreciation (20 ) (20 ) Amortization of intangible assets (8 ) (8 ) Stock-based compensation (29 ) (29 ) Operating income 23 Other expense, net (2 ) Income before income taxes 21 Provision for income taxes (16 ) Net income 5 Three months ended March 31, 2017 Hotel Non-Hotel Corporate and Unallocated Total (in millions) Revenue $ 314 $ 58 $ - $ 372 Adjusted EBITDA (1) 88 (15 ) - 73 Depreciation (19 ) (19 ) Amortization of intangible assets (8 ) (8 ) Stock-based compensation (19 ) (19 ) Operating income 27 Other expense, net (2 ) Income before income taxes 25 Provision for income taxes (12 ) Net income 13 (1) Includes allocated general and administrative expenses in our Hotel segment of $20 million and $19 million; and in our Non-Hotel segment of $12 million and $9 million for the three months ended March 31, 2018 and 2017, respectively.

Business Description and Basi28

Business Description and Basis of Presentation - Additional Information (Details)	3 Months Ended
	Mar. 31, 2018MarketLanguageBrandSegment
Accounting Policies [Abstract]
Number of markets with localized versions of website | Market	48
Number of languages worldwide | Language	28
Number of other media brands with websites | Brand	20
Number of reportable segment | Segment	2

Significant Accounting Polici29

Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions	Jan. 01, 2018	Mar. 31, 2018
Schedule Of Accounting Policies [Line Items]
Recorded a net increase in opening retained earnings		$ 4
ASC 606
Schedule Of Accounting Policies [Line Items]
Recorded a net increase in opening retained earnings	$ 4

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)Segment
Disaggregation Of Revenue [Line Items]
Number of reportable segment | Segment	2
Revenue recognized	$ 41
ASC 606
Disaggregation Of Revenue [Line Items]
Customer invoices due period	30 days
Capitalized costs to obtain a contract	$ 1
Transaction price related to unsatisfied performance obligations expected period	1 year

Revenue Recognition - Summary o

Revenue Recognition - Summary of Impact of New Revenue Recognition Guidance on Unaudited Condensed Consolidated Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Revenue (Note 3)	$ 378	$ 372
Operating income	23	27
Income before income taxes	21	25
Provision for income taxes	(16)	(12)
Net income	5	$ 13
ASC 606 | Impact of Accounting Under ASC 606
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Revenue (Note 3)	(4)
Operating income	(4)
Income before income taxes	(4)
Provision for income taxes	1
Net income	(3)
ASC 606 | Adjusted - ASC 605
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Revenue (Note 3)	374
Operating income	19
Income before income taxes	17
Provision for income taxes	(15)
Net income	$ 2

Revenue Recognition - Reconcili

Revenue Recognition - Reconciliation of Disaggregated Revenue to Segment Revenue (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 378
Hotel Segment
Disaggregation Of Revenue [Line Items]
Total Revenue	299	[1]
Non-Hotel Segment
Disaggregation Of Revenue [Line Items]
Total Revenue	79	[1]
Click-Based Advertising and Transaction Revenue | Hotel Segment
Disaggregation Of Revenue [Line Items]
Total Revenue	189
Display-Based Advertising and Subscription Revenue | Hotel Segment
Disaggregation Of Revenue [Line Items]
Total Revenue	71
Other Hotel Revenue | Hotel Segment
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 39
[1]	Our revenue is recognized primarily at a point in time for both our Hotel and Non-Hotel segments.

Revenue Recognition - Summary33

Revenue Recognition - Summary of Balances of Accounts Receivables and Contract Assets from Contracts with Customers (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Revenue From Contract With Customer [Abstract]
Accounts receivable	$ 269	$ 230
Contract assets	12
Total	$ 281	$ 230

Earnings Per Share - Reconcilia

Earnings Per Share - Reconciliation of Weighted Average Number of Shares of Common Stock Outstanding In Calculating EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net income	$ 5	$ 13
Denominator:
Weighted average shares used to compute Basic EPS	139,312	143,632
Weighted average effect of dilutive securities:
Stock options	118	516
RSUs/MSUs	892	569
Weighted average shares used to compute Diluted EPS	140,322	144,717
Basic EPS	$ 0.04	$ 0.09
Diluted EPS	$ 0.04	$ 0.09

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details) - Stock Options, RSUs and MSUs - shares shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	12	6.4
Performance Shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0.4	0.1

Stock Based Awards and Other 36

Stock Based Awards and Other Equity Instruments - Amount of Stock-Based Compensation Expense Related to Stock-Based Awards, Primarily Stock Options and RSUs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 29	$ 19
Income tax benefit from stock-based compensation	(7)	(7)
Total stock-based compensation, net of tax effect	22	12
Selling and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	6	5
Technology and Content
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	12	7
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 11	$ 7

Stock Based Awards and Other 37

Stock Based Awards and Other Equity Instruments - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Capitalized stock based compensation as internal-use software and website development costs	$ 3	$ 3
Cash received from stock option exercises		3
Income tax benefits from exercise or settlement of stock-based awards	$ 3	14
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of stock options issued	611,000
RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSU's issued under incentive plan	2,590,000
2011 Plan | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of stock options issued	611,235
Term of stock options, granted	10 years
Stock awards vest period	4 years
Closing stock price	$ 40.89
Total intrinsic value	$ 3	$ 7
Weighted-average grant date fair value of options granted	$ 17.60	$ 17.20
Total fair value of stock options vested	$ 8	$ 13
Cash received from stock option exercises		$ 3
2011 Plan | RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock awards vest period	4 years
RSU's issued under incentive plan	2,590,380

Stock Based Awards and Other 38

Stock Based Awards and Other Equity Instruments - Summary of Stock Option Activity (Details) - Stock Options $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Options Outstanding
Options Outstanding, Beginning balance | shares	6,853
Options Outstanding, Granted | shares	611
Options Outstanding, Exercised | shares	(196)	[1]
Options Outstanding, Cancelled or expired | shares	(72)
Options Outstanding, Ending balance | shares	7,196
Options Outstanding, Exercisable | shares	3,428
Options Outstanding, Vested and expected to vest | shares	7,196	[2]
Weighted Average Exercise Price per share
Options Outstanding, Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 52.78
Options Granted, Weighted Average Exercise Price | $ / shares	41.54
Options Exercised, Weighted Average Exercise Price | $ / shares	28.21	[1]
Options Cancelled or expired, Weighted Average Exercise Price | $ / shares	47.80
Options Outstanding, Weighted Average Exercise Price, Ending balance | $ / shares	52.48
Options Exercisable, Weighted Average Exercise Price | $ / shares	54.81
Options Vested and expected to vest, Weighted Average Exercise Price | $ / shares	$ 52.48	[2]
Weighted Average Remaining Contractual Life and Aggregate Intrinsic Value
Options Outstanding, Weighted Average Remaining Contractual Life	6 years 8 months 12 days
Options Exercisable, Weighted Average Remaining Contractual Life	4 years 8 months 12 days
Options Vested and expected to vest, Weighted Average Remaining Contractual Life	6 years 8 months 12 days	[2]
Options Outstanding, Aggregate Intrinsic Value | $	$ 10
Options Exercisable, Aggregate Intrinsic Value | $	5
Options Vested and expected to vest, Aggregate Intrinsic Value | $	$ 10	[2]
[1]	Inclusive of 150,855 of options which were not converted into shares due to net share settlement in order to cover the aggregate exercise price and the required amount of employee withholding taxes. Potential shares that had been convertible under stock options that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the unaudited condensed consolidated statements of cash flows.
[2]	The Company accounts for forfeitures as they occur, rather than estimate expected forfeitures as allowed under GAAP and therefore do not include a forfeiture rate in our vested and expected to vest calculation unless necessary for a performance condition award.

Stock Based Awards and Other 39

Stock Based Awards and Other Equity Instruments - Summary of Stock Option Activity (Parenthetical) (Details)	3 Months Ended
	Mar. 31, 2018shares
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options non converted into shares due to net share settlement	150,855

Stock Based Awards and Other 40

Stock Based Awards and Other Equity Instruments - Weighted-Average Assumptions of Estimated Fair Value of Stock Option Grants (Details)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk free interest rate	2.66%	1.91%
Expected term (in years)	5 years 5 months 12 days	5 years 4 months 6 days
Expected volatility	42.29%	41.53%

Stock Based Awards and Other 41

Stock Based Awards and Other Equity Instruments - Summary of RSU Activity, Including Service Based Awards and Performance-Based Awards (Details) - Restricted Stock Units $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
RSUs outstanding
Unvested outstanding, Beginning balance | shares	6,015
Unvested RSUs, Transfer | shares	(213)	[1]
Unvested RSUs, Granted | shares	2,590
Unvested RSUs, Vested and released | shares	(1,007)	[2]
Unvested RSUs, Cancelled | shares	(160)
Unvested outstanding, Ending balance | shares	7,225
RSUs outstanding, Expected to vest | shares	7,225	[3]
Weighted Average Grant-Date Fair Value Per Share
Unvested outstanding, Weighted Average Grant-Date Fair Value Per Share, Beginning balance | $ / shares	$ 48.14
Weighted Average Grant-Date Fair Value Per Share, Transfer | $ / shares	30.04	[1]
Weighted Average Grant-Date Fair Value Per Share, Granted | $ / shares	41.44
Weighted Average Grant-Date Fair Value Per Share, Vested and released | $ / shares	56.11	[2]
Weighted Average Grant-Date Fair Value Per Share, Cancelled | $ / shares	47.26
Unvested outstanding, Weighted Average Grant-Date Fair Value Per Share, Ending balance | $ / shares	45.18
Weighted Average Grant-Date Fair Value Per Share, Expected to vest | $ / shares	$ 45.18	[3]
Aggregate Intrinsic Value
Unvested RSUs outstanding, Aggregate Intrinsic Value | $	$ 295
RSUs Vested and expected to vest, Aggregate Intrinsic Value | $	$ 295
[1]	RSUs outstanding as of December 31, 2017 include 213,000 MSUs awarded to the Company’s CEO in November 2017. This award has been transferred to the MSU activity table below.
[2]	Inclusive of 269,878 RSUs withheld due to net share settlement to satisfy required employee tax withholding requirements. Potential shares which had been convertible under RSUs that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the unaudited condensed consolidated statements of cash flows.
[3]	The Company accounts for forfeitures as they occur, rather than estimate expected forfeitures as allowed under GAAP and therefore do not include a forfeiture rate in our expected to vest calculation unless necessary for a performance condition award.

Stock Based Awards and Other 42

Stock Based Awards and Other Equity Instruments - Summary of RSU Activity, Including Service Based Awards and Performance-Based Awards (Parenthetical) (Details) - Restricted Stock Units - shares		1 Months Ended	3 Months Ended
		Nov. 30, 2017	Mar. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share transfer award	[1]		213,000
RSUs withheld to satisfy withholding tax requirements			269,878
CEO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share transfer award		213,000
[1]	RSUs outstanding as of December 31, 2017 include 213,000 MSUs awarded to the Company’s CEO in November 2017. This award has been transferred to the MSU activity table below.

Stock Based Awards and Other 43

Stock Based Awards and Other Equity Instruments - Summary of RSU Activity For MSUs (Details) - MSUs $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
MSUs outstanding
Unvested outstanding, Beginning balance | shares	213	[1]
Unvested MSUs, Granted | shares	71	[2]
Unvested outstanding, Ending balance | shares	284
Weighted Average Grant-Date Fair Value Per Share
Unvested outstanding, Weighted Average Grant-Date Fair Value Per Share, Beginning balance | $ / shares	$ 30.04	[1]
Weighted Average Grant-Date Fair Value Per Share, Granted | $ / shares	59.40	[2]
Unvested outstanding, Weighted Average Grant-Date Fair Value Per Share, Ending balance | $ / shares	$ 37.41
Aggregate Intrinsic Value
Unvested MSUs outstanding, Aggregate Intrinsic Value | $	$ 12
[1]	Represents 213,000 MSUs awarded to the Company’s CEO in November 2017.
[2]	MSUs provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2018 through December 31, 2020 relative to the TSR performance of the Nasdaq Composite Total Return Index. A Monte-Carlo simulation model, which simulated the present value of the potential outcomes of future stock prices and TSR of the Company and the Nasdaq Composite Total Return Index over the performance period, was used to calculate the grant-date fair value of these awards. The estimated grant-date fair value of these awards is being amortized on a straight-line basis over the requisite service period through December 31, 2020. Based upon actual attainment relative to the target performance metric, the grantee has the ability to receive up to 200% of the target number of MSUs originally granted, or to be issued none at all.

Stock Based Awards and Other 44

Stock Based Awards and Other Equity Instruments - Summary of RSU Activity For MSUs (Parenthetical) (Details) - MSUs - shares	1 Months Ended	3 Months Ended
	Nov. 30, 2017	Mar. 31, 2018
Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of originally granted shares that may be earned upon performance achievement, maximum		200.00%
Percentage of originally granted shares that may be earned upon performance achievement, minimum		0.00%
Requisite service period for estimated grant-date fair value of stock awards		Dec. 31, 2020
Stock awards vesting term		MSUs provide for vesting based upon the Company’s total shareholder return, or TSR, performance over the period commencing January 1, 2018 through December 31, 2020 relative to the TSR performance of the Nasdaq Composite Total Return Index.
Performance measurement period start date		Jan. 1, 2018
Performance measurement period end date		Dec. 31, 2020
CEO
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share transfer award	213,000

Stock Based Awards and Other 45

Stock Based Awards and Other Equity Instruments -Summary of Unrecognized Stock-Based Compensation Expense and Weighted Average Period Remaining (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense	$ 55
Weighted average period remaining (in years)	3 years
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average period remaining (in years)	3 years 2 months 12 days
Unrecognized compensation expense, RSUs and MSUs	$ 302
MSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average period remaining (in years)	2 years 9 months 18 days
Unrecognized compensation expense, RSUs and MSUs	$ 10

Financial Instruments - Schedul

Financial Instruments - Schedule of Cash, Cash Equivalents, Restricted Cash and Marketable Securities (Details) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and Cash Equivalents		$ 635	$ 673
Short-Term Marketable Securities		15	35
Long-Term Marketable Securities		5	27
Cash	[1]	340	663
Cash equivalents	[1]	340	663
Cash, cash equivalents, restricted cash and marketable securities, amortized cost		655	735
Cash, cash equivalents, restricted cash and marketable securities, fair value		655	735
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		295	1
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		20	71
Fair Value		20	71
Cash and Cash Equivalents			9
Short-Term Marketable Securities		15	35
Long-Term Marketable Securities		5	27
Level 2 | U.S. Agency Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		4	11
Fair Value		4	11
Short-Term Marketable Securities		4	6
Long-Term Marketable Securities			5
Level 2 | US treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost			1
Fair Value			1
Short-Term Marketable Securities			1
Level 2 | Certificates of Deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		2	2
Fair Value		2	2
Short-Term Marketable Securities		2	2
Level 2 | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost			11
Fair Value			11
Cash and Cash Equivalents			9
Short-Term Marketable Securities			2
Level 2 | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		14	46
Fair Value		14	46
Short-Term Marketable Securities		9	24
Long-Term Marketable Securities		$ 5	$ 22
[1]	As of March 31, 2018 and December 31, 2017, our restricted cash which primarily consists of escrowed security deposits, was not material and is included in other long-term assets on our unaudited condensed consolidated balance sheets.

Financial Instruments - Additio

Financial Instruments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Financial instruments including money market funds maturities period	90 days	90 days
Maximum maturities period of long-term marketable securities	3 years	3 years
Minimum maturities period of long-term marketable securities	1 year	1 year
Maximum remaining maturity for short-term marketable securities	12 months	12 months
Minimum maturities of short-term marketable securities	90 days	90 days
Derivative instruments not designated as hedging instruments, description of terms	Derivative financial instruments are carried at fair value on our unaudited condensed consolidated balance sheets. We use foreign currency forward contracts to reduce the effects of foreign currency exchange rate fluctuations on our cash flows primarily for the Euro versus the U.S. Dollar. Our foreign currency forward contracts, which we have entered into to date, have not been designated as hedges and have had current maturities of less than 90 days
Cost method investments	$ 12	$ 12

Debt - Summary of Total Outstan

Debt - Summary of Total Outstanding Debt (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Short-Term Debt:
Short-Term Debt	$ 7	$ 7
Long-Term Debt:
Long-Term Debt		230
Chinese Credit Facilities
Short-Term Debt:
Credit Facilities	$ 7	7
2015 Credit Facility
Long-Term Debt:
Credit Facilities		$ 230

Debt - Two Thousand Fifteen Cre

Debt - Two Thousand Fifteen Credit Facility - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Total interest expense and commitments fees	$ 3,000,000	$ 3,000,000
2015 Credit Facility
Debt Instrument [Line Items]
Total interest expense and commitments fees	1,000,000	$ 1,000,000
2015 Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Borrowing capacity under Credit Facility	$ 1,200,000,000
Interest rate description	Borrowings under the 2015 Credit Facility generally bear interest, at the Company’s option, at a rate per annum equal to either (i) the Eurocurrency Borrowing rate, or the adjusted LIBO rate for the interest period in effect for such borrowing; plus an applicable margin ranging from 1.25% to 2.00% (“Eurocurrency Spread”), based on the Company’s leverage ratio; or (ii) the Alternate Base Rate (“ABR”) Borrowing, which is the greatest of (a) the Prime Rate in effect on such day, (b) the New York Fed Bank Rate in effect on such day plus 1/2 of 1.00% per annum and (c) the Adjusted LIBO Rate (or LIBO rate multiplied by the Statutory Reserve Rate) for an interest period of one month plus 1.00%; in addition to an applicable margin ranging from 0.25% to 1.00% (“ABR Spread”), based on the Company’s leverage ratio.
Credit facility, maturity date	May 12, 2022
Credit facility, expiration period	5 years
Line of credit facility additional borrowing	$ 5,000,000
Repayments of Debt	235,000,000
Cash repatriation of foreign earnings	325,000,000
Outstanding borrowings	$ 0
Line Of Credit Facility Unused Capacity Commitment Fee Percentage	0.15%
2015 Credit Facility | Letter of Credit
Debt Instrument [Line Items]
Borrowing capacity under Credit Facility	$ 15,000,000
Letters of credit outstanding amount	3,000,000
2015 Credit Facility | Borrowings On Same Day Notice
Debt Instrument [Line Items]
Borrowing capacity under Credit Facility	$ 40,000,000
2015 Credit Facility | Minimum | Revolving Credit Facility
Debt Instrument [Line Items]
Line Of Credit Facility Unused Capacity Commitment Fee Percentage	0.15%
2015 Credit Facility | Minimum | Revolving Credit Facility | Eurocurrency Spread
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
2015 Credit Facility | Minimum | Revolving Credit Facility | Adjusted London Interbank Offered Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.25%
2015 Credit Facility | Minimum | Revolving Credit Facility | ABR Spread
Debt Instrument [Line Items]
Basis spread on variable rate	0.25%
2015 Credit Facility | Maximum | Revolving Credit Facility
Debt Instrument [Line Items]
Line Of Credit Facility Unused Capacity Commitment Fee Percentage	0.30%
2015 Credit Facility | Maximum | Revolving Credit Facility | Eurocurrency Spread
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%
2015 Credit Facility | Maximum | Revolving Credit Facility | Adjusted London Interbank Offered Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
2015 Credit Facility | Maximum | Revolving Credit Facility | ABR Spread
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%

Debt - Two Thousand Sixteen Cre

Debt - Two Thousand Sixteen Credit Facility - Additional Information (Details) - 2016 Credit Facility - Revolving Credit Facility - Lender - USD ($)	3 Months Ended
	Mar. 31, 2018	Sep. 07, 2016
Debt Instrument [Line Items]
Borrowing capacity under Credit Facility		$ 73,000,000
Credit Facility, description	The Company may borrow from the 2016 Credit Facility in U.S. dollars only and we may voluntarily repay any outstanding borrowing at any time without premium or penalty.
Outstanding borrowings	$ 0
Minimum
Debt Instrument [Line Items]
Repayment term of borrowings	1 month
Maximum
Debt Instrument [Line Items]
Repayment term of borrowings	6 months
London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate	1.125%
Borrowings, interest rate description	bear interest at LIBO rate plus 112.5 basis points

Debt - Chinese Credit Facilitie

Debt - Chinese Credit Facilities - Additional Information (Details) - Chinese Credit Facilities	3 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2017CreditFacility	Mar. 31, 2018CNY (¥)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Number of credit facilities | CreditFacility		2
Outstanding borrowings	$ 7,000,000			$ 7,000,000
Chinese Credit Facility Boa
Debt Instrument [Line Items]
Borrowing capacity under Credit Facility	$ 30,000,000
Period of credit facility	1 year
Interest rate description	Borrowings under our Chinese Credit Facility – BOA generally bear interest at a rate based on People’s Bank of China benchmark, including certain adjustments which may be made in accordance with market conditions at the time of borrowing.
Outstanding borrowings	$ 0			0
Chinese Credit Facility JPM
Debt Instrument [Line Items]
Borrowing capacity under Credit Facility	$ 11,000,000		¥ 70,000,000
Period of credit facility	1 year
Interest rate description	Our Chinese Credit Facility—JPM generally bears interest at a rate based on People’s Bank of China benchmark, including certain adjustments which may be made in accordance with market conditions at the time of borrowing.
Outstanding borrowings	$ 7,000,000			$ 7,000,000
Line of credit, interest rate basis	4.98%		4.98%	5.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Taxes [Line Items]
Effective tax rate		76.20%	48.00%
Income tax expense at federal statutory rate		21.00%		35.00%
Incremental transition tax expense		$ 5,000,000
Tax cuts and jobs act, income tax benefit		1,000,000
Accrued interest		11,000,000
Accrued penalties		0
Tax benefit from subsidiary		$ 1,000,000	$ 1,000,000
Minimum | Expedia | IRS | Tax Years 2009 and 2010
Income Taxes [Line Items]
Increase in income tax expense due to proposed adjustments related to transfer pricing with foreign subsidiary, estimated	$ 10,000,000
Maximum | Expedia | IRS | Tax Years 2009 and 2010
Income Taxes [Line Items]
Increase in income tax expense due to proposed adjustments related to transfer pricing with foreign subsidiary, estimated	$ 14,000,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)	Apr. 01, 2018	Mar. 31, 2018	May 07, 2018	Jan. 31, 2018
Schedule Of Capitalization Equity [Line Items]
Authorized the repurchase of shares of common stock				$ 250,000,000
Repurchase of common stock, shares		252,650
Aggregate cost of shares repurchased, common stock		$ 10,000,000
Average price of shares repurchased, common stock		$ 39.88
Remaining amounts payable recorded in accrued expenses and other current liabilities		$ 6,000,000
Remaining authorized share repurchased amount		$ 240,000,000
Subsequent Event
Schedule Of Capitalization Equity [Line Items]
Repurchase of common stock, shares	2,329,548
Aggregate cost of shares repurchased, common stock	$ 90,000,000
Average price of shares repurchased, common stock	$ 38.60
Remaining authorized share repurchased amount			$ 150,000,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - LTRIP - USD ($) shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Related Party Transaction [Line Items]
Beneficially ownership of shares of common stock	18.2
Percentage taken from outstanding shares of common stock	14.30%
Percentage of beneficially ownership of shares of common stock class B	22.20%
Right to voting	one vote per share
Beneficially ownership of equity securities	57.40%
Related party transactions	$ 0	$ 0
Class B Common Stock
Related Party Transaction [Line Items]
Beneficially ownership of shares of common stock	12.8
Percentage taken from outstanding shares of common stock	100.00%
Right to voting	Ten votes per share

Segment Information - Additiona

Segment Information - Additional Information (Details)	3 Months Ended
	Mar. 31, 2018Segment
Segment Reporting Information [Line Items]
Number of reportable segment	2
Non-Hotel Segment
Segment Reporting Information [Line Items]
Number of operating segments	3

Segment Information - Summary o

Segment Information - Summary of Segment Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenue		$ 378	$ 372
Adjusted EBITDA	[1]	80	73
Depreciation		(20)	(19)
Amortization of intangible assets		(8)	(8)
Stock-based compensation		(29)	(19)
Operating income		23	27
Other expense, net		(2)	(2)
Income before income taxes		21	25
Provision for income taxes		(16)	(12)
Net income		5	13
Operating Segments | Hotel Segment
Segment Reporting Information [Line Items]
Revenue		299	314
Adjusted EBITDA	[1]	88	88
Operating Segments | Non-Hotel Segment
Segment Reporting Information [Line Items]
Revenue		79	58
Adjusted EBITDA	[1]	(8)	(15)
Corporate and Unallocated
Segment Reporting Information [Line Items]
Depreciation		(20)	(19)
Amortization of intangible assets		(8)	(8)
Stock-based compensation		$ (29)	$ (19)
[1]	Includes allocated general and administrative expenses in our Hotel segment of $20 million and $19 million; and in our Non-Hotel segment of $12 million and $9 million for the three months ended March 31, 2018 and 2017, respectively.

Segment Information - Summary57

Segment Information - Summary of Segment Information (Parenthetical) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
General and administrative	[1]	$ 42	$ 35
Operating Segments | Hotel Segment
Segment Reporting Information [Line Items]
General and administrative		20	19
Operating Segments | Non-Hotel Segment
Segment Reporting Information [Line Items]
General and administrative		$ 12	$ 9
[1]	Includes stock-based compensation expense as follows