Booking (BKNG) 10-K19 Feb 152014 FY Annual reportFinancial data

Company Profile

DOCUMENT_AND_ENTITY_INFORMATIO

DOCUMENT AND ENTITY INFORMATION (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 11, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	Priceline Group Inc.
Entity Central Index Key	1075531
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		51,939,191
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$62.80

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$3,148,651	$1,289,994
Restricted cash	843	10,476
Short-term investments	1,142,182	5,462,720
Accounts receivable, net of allowance for doubtful accounts of $14,212 and $14,116, respectively	643,894	535,962
Prepaid expenses and other current assets	178,050	107,102
Deferred income taxes	153,754	74,687
Total current assets	5,267,374	7,480,941
Property and equipment, net	198,953	135,053
Intangible assets, net	2,334,761	1,019,985
Goodwill	3,326,474	1,767,912
Long-term investments	3,755,653	0
Other assets	57,348	40,569
Total assets	14,940,563	10,444,460
Current liabilities:
Accounts payable	281,480	247,345
Accrued expenses and other current liabilities	600,758	545,342
Deferred merchant bookings	460,558	437,127
Convertible debt	37,195	151,931
Total current liabilities	1,379,991	1,381,745
Deferred income taxes	1,040,260	326,425
Other long-term liabilities	103,533	75,981
Long-term debt	3,849,756	1,742,047
Total liabilities	6,373,540	3,526,198
Commitments and Contingencies (See Note 16)
Convertible debt	329	8,533
Stockholders' equity:
Common stock, $0.008 par value, authorized 1,000,000,000 shares, 61,821,097 and 61,265,160 shares issued, respectively	480	476
Treasury stock, 9,888,024 and 9,256,721, respectively	-2,737,585	-1,987,207
Additional paid-in capital	4,923,196	4,592,979
Accumulated earnings	6,640,505	4,218,752
Accumulated other comprehensive income (loss)	-259,902	84,729
Total stockholders' equity	8,566,694	6,909,729
Total liabilities and stockholders' equity	$14,940,563	$10,444,460

CONSOLIDATED_BALANCE_SHEETS_PA

CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$14,212	$14,116
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, authorized shares (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	61,821,097	61,265,160
Treasury stock, shares (in shares)	9,888,024	9,256,721

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Agency revenues	$5,845,802	$4,410,689	$3,142,815
Merchant revenues	2,186,054	2,211,474	2,104,752
Advertising and other revenues	410,115	171,143	13,389
Total revenues	8,441,971	6,793,306	5,260,956
Cost of revenues	857,841	1,077,420	1,177,275
Gross profit	7,584,130	5,715,886	4,083,681
Operating expenses:
Advertising b Online	2,360,221	1,798,645	1,273,637
Advertising b Offline	231,309	127,459	35,492
Sales and marketing	310,910	235,817	195,934
Personnel, including stock-based compensation of $186,425, $140,526 and $71,565, respectively	950,191	698,692	466,828
General and administrative	352,869	252,994	173,171
Information technology	97,498	71,890	43,685
Depreciation and amortization	207,820	117,975	65,141
Total operating expenses	4,510,818	3,303,472	2,253,888
Operating income	3,073,312	2,412,414	1,829,793
Other income (expense):
Interest income	13,933	4,167	3,860
Interest expense	-88,353	-83,289	-62,064
Foreign currency transactions and other	-9,444	-36,755	-9,720
Total other income (expense)	-83,864	-115,877	-67,924
Earnings before income taxes	2,989,448	2,296,537	1,761,869
Income tax expense	567,695	403,739	337,832
Net income	2,421,753	1,892,798	1,424,037
Less: net income attributable to noncontrolling interests	0	135	4,471
Net income applicable to common stockholders	$2,421,753	$1,892,663	$1,419,566
Net income applicable to common stockholders per basic common share	$46.30	$37.17	$28.48
Weighted average number of basic common shares outstanding	52,301	50,924	49,840
Net income applicable to common stockholders per diluted common share	$45.67	$36.11	$27.66
Weighted average number of diluted common shares outstanding	53,023	52,413	51,326

CONSOLIDATED_STATEMENTS_OF_OPE1

CONSOLIDATED STATEMENTS OF OPERATIONS (PARENTHETICAL) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Stock-based compensation	$186,425	$140,526	$71,565

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$2,421,753		$1,892,798		$1,424,037
Other comprehensive income (loss), net of tax
Foreign currency translation adjustments	-187,356	[1]	97,970	[1]	69,683	[1]
Unrealized gain (loss) on marketable securities	-157,275	[2]	21	[2]	-620	[2]
Comprehensive income	2,077,122		1,990,789		1,493,100
Less: Comprehensive income (loss) attributable to redeemable noncontrolling interests	0		-10,279		9,628
Comprehensive income attributable to common stockholders	2,077,122		2,001,068		1,483,472
Foreign currency translation adjustment for net investment hedges arising during the period, tax (tax benefit)	55,597		-55,001		-18,001
Unrealized gain (loss) on marketable securities arising during period, tax (tax benefit)	($7,621)		($43)		($158)

[1]	Foreign currency translation adjustments includes a tax of $55,597 for the year ended DecemberB 31, 2014 and tax benefits of $55,001 and $18,001 for the years ended DecemberB 31, 2013 and 2012, respectively, associated with hedges of foreign denominated net assets (See Note 14). The remaining balance in currency translation adjustments excludes income taxes due to the Company's practice and intention to reinvest the earnings of its foreign subsidiaries in those operations (See Note 15).
[2]	Net of tax benefits of $7,621, $43 and $158 for the years ended DecemberB 31, 2014, 2013 and 2012, respectively.

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $)	Total		Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Earnings	Accumulated Other Comprehensive Income (Loss)
In Thousands, except Share data, unless otherwise specified	Total		Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2011	$2,574,295		$446	($803,586)	$2,431,279	$1,033,738	($87,582)
Balance (in shares) at Dec. 31, 2011			-57,579,000	-7,780,000
Increase (Decrease) in Stockholders' Equity
Net income applicable to common stockholders	1,419,566					1,419,566
Unrealized gain (loss) on marketable securities, net of tax benefit	-620	[1]					-620
Currency translation adjustments, net of tax	64,526						64,526
Redeemable noncontrolling interests fair value adjustments	-84,693				0	-84,693
Reclassification adjustment for convertible debt in mezzanine	22,705				22,705
Exercise of stock options and vesting of restricted stock units and performance share units	2,683		4		2,679
Exercise of stock options and vesting of restricted stock units and performance share units (in shares)			477,000
Repurchase of common stock	-257,021			-257,021
Repurchase of common stock (in shares)				-405,000
Stock-based compensation and other stock-based payments	72,035				72,035
Issuance of senior convertible notes	78,310				78,310
Excess tax benefit from stock-based compensation	5,189				5,189
Balance at Dec. 31, 2012	3,896,975		450	-1,060,607	2,612,197	2,368,611	-23,676
Balance (in shares) at Dec. 31, 2012			-58,056,000	-8,185,000
Increase (Decrease) in Stockholders' Equity
Net income applicable to common stockholders	1,892,663					1,892,663
Unrealized gain (loss) on marketable securities, net of tax benefit	21	[1]					21
Currency translation adjustments, net of tax	108,384						108,384
Redeemable noncontrolling interests fair value adjustments	-42,522					-42,522
Reclassification adjustment for convertible debt in mezzanine	46,122				46,122
Exercise of stock options and vesting of restricted stock units and performance share units	91,607		6		91,601
Exercise of stock options and vesting of restricted stock units and performance share units (in shares)			715,000
Repurchase of common stock	-883,515			-883,515
Repurchase of common stock (in shares)				-1,030,000
Stock-based compensation and other stock-based payments	142,098				142,098
Conversion of debt	1,232		8		1,224
Conversion of debt (in shares)			972,000
Issuance of senior convertible notes	93,402				93,402
Common stock issued in an acquisition	1,281,134		12		1,281,122
Common stock issued in an acquisition (in shares)			1,522,000
Equity assumed in acquisition	264,423				264,423
Settlement of conversion spread hedges	-19			-43,085	-43,104
Settlement of conversion spread hedges, shares				-42,000
Excess tax benefit from stock-based compensation	17,686				17,686
Balance at Dec. 31, 2013	6,909,729		476	-1,987,207	4,592,979	4,218,752	84,729
Balance (in shares) at Dec. 31, 2013			-61,265,000	-9,257,000
Increase (Decrease) in Stockholders' Equity
Net income applicable to common stockholders	2,421,753					2,421,753
Unrealized gain (loss) on marketable securities, net of tax benefit	-157,275	[1]					-157,275
Currency translation adjustments, net of tax	-187,356						-187,356
Redeemable noncontrolling interests fair value adjustments	0
Reclassification adjustment for convertible debt in mezzanine	8,204				8,204
Exercise of stock options and vesting of restricted stock units and performance share units	16,391		2		16,389
Exercise of stock options and vesting of restricted stock units and performance share units (in shares)			256,000
Repurchase of common stock	-750,378			-750,378
Repurchase of common stock (in shares)				-631,000
Stock-based compensation and other stock-based payments	189,292				189,292
Conversion of debt	-1,656		2		-1,658
Conversion of debt (in shares)			300,000
Issuance of senior convertible notes	80,873				80,873
Equity assumed in acquisition	13,751				13,751
Excess tax benefit from stock-based compensation	23,366				23,366
Balance at Dec. 31, 2014	$8,566,694		$480	($2,737,585)	$4,923,196	$6,640,505	($259,902)
Balance (in shares) at Dec. 31, 2014			-61,821,000	-9,888,000

[1]	Net of tax benefits of $7,621, $43 and $158 for the years ended DecemberB 31, 2014, 2013 and 2012, respectively.

CONSOLIDATED_STATEMENTS_OF_CHA1

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (PARENTHETICAL) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Unrealized gain (loss) on marketable securities arising during period, tax expense (benefit)	($7,621)	($43)	($158)
Currency translation adjustment, tax expense (benefit)	$55,597	($55,001)	($18,001)

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
OPERATING ACTIVITIES:
Net income	$2,421,753	$1,892,798	$1,424,037
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	78,241	48,365	32,818
Amortization	129,579	69,610	32,323
Provision for uncollectible accounts, net	22,990	16,451	16,094
Deferred income tax expense (benefit)	31,707	-11,104	19,596
Stock-based compensation expense and other stock based payments	189,292	142,098	72,035
Amortization of debt issuance costs	5,229	7,898	5,212
Amortization of debt discount	54,731	55,718	39,820
Loss on early extinguishment of debt	6,270	26,661	0
Changes in assets and liabilities:
Accounts receivable	-182,209	-111,572	-105,277
Prepaid expenses and other current assets	-48,932	-6,909	-40,793
Accounts payable, accrued expenses and other current liabilities	203,870	182,163	256,021
Other	1,876	-10,741	33,864
Net cash provided by operating activities	2,914,397	2,301,436	1,785,750
INVESTING ACTIVITIES:
Purchase of investments	-10,552,214	-9,955,800	-6,352,495
Proceeds from sale of investments	10,902,500	8,291,283	4,799,412
Additions to property and equipment	-131,504	-84,445	-55,158
Acquisitions and other equity investments, net of cash acquired	-2,496,366	-331,918	-33,861
Proceeds from foreign currency contracts	14,354	3,266	86,159
Payments on foreign currency contracts	-94,661	-81,870	-4,014
Change in restricted cash	9,347	-2,783	-2,756
Net cash used in investing activities	-2,348,544	-2,162,267	-1,562,713
FINANCING ACTIVITIES:
Proceeds from revolving credit facility	995,000	0	0
Payments related to revolving credit facility	-995,000	0	0
Proceeds from the issuance of long-term debt	2,282,217	980,000	1,000,000
Payment of debt issuance costs	-17,464	-1,018	-20,916
Payments related to conversion of senior notes	-125,136	-414,569	-1
Repurchase of common stock	-750,378	-883,515	-257,021
Payments to purchase subsidiary shares from noncontrolling interests	0	-192,530	-61,079
Payments of stock issuance costs	0	-1,191	0
Proceeds from exercise of stock options	16,389	91,607	2,683
Proceeds from the termination of conversion spread hedges	0	19	0
Excess tax benefit from stock-based compensation	23,366	17,686	5,189
Net cash provided by (used in) financing activities	1,428,994	-403,511	668,855
Effect of exchange rate changes on cash and cash equivalents	-136,190	17,987	11,621
Net increase (decrease) in cash and cash equivalents	1,858,657	-246,355	903,513
Cash and cash equivalents, beginning of period	1,289,994	1,536,349	632,836
Cash and cash equivalents, end of period	3,148,651	1,289,994	1,536,349
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid during the period for income taxes	491,530	391,169	300,539
Cash paid during the period for interest	16,950	20,954	13,933
Non-cash fair value increase for redeemable noncontrolling interests	0	42,522	84,693
Non-cash investing activity for contingent consideration	10,700	0	0
Non-cash financing activity for acquisitions	$13,751	$1,546,748	$0

BUSINESS_DESCRIPTION

BUSINESS DESCRIPTION	12 Months Ended
BUSINESS DESCRIPTION	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BUSINESS DESCRIPTION	BUSINESS DESCRIPTION

	On April 1, 2014, the Company changed its name from priceline.com Incorporated to The Priceline Group Inc. The Priceline Group Inc. ("The Priceline Group" or the "Company") is a leading provider of online travel and travel related reservation and search services. Through the Company's online travel agent ("OTA") services, the Company connects consumers wishing to make travel reservations with providers of travel services around the world. The Company offers consumers accommodation reservations (including hotels, bed and breakfasts, hostels, apartments, vacation rentals and other properties) through its Booking.com, priceline.com and agoda.com brands. The Company's priceline.com brand also offers consumers reservations for rental cars, airline tickets, vacation packages and cruises. The Company offers rental car reservations worldwide through rentalcars.com. The Company also allows consumers to easily compare airline ticket, hotel reservation and rental car reservation information from hundreds of travel websites at once through KAYAK. The Company acquired OpenTable, a leading provider of online restaurant reservations in July 2014.

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	Dec. 31, 2014
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

	Basis of Presentation — The Company's Consolidated Financial Statements include the accounts of the Company and its wholly-owned subsidiaries, including KAYAK Software Corporation ("KAYAK") since its acquisition in May 2013 and OpenTable, Inc. ("OpenTable") since its acquisition in July 2014. All intercompany accounts and transactions have been eliminated in consolidation.

	Use of Estimates — The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and footnotes thereto. Actual results may differ significantly from those estimates. The estimates underlying the Company's Consolidated Financial Statements relate to, among other things, the accrual for travel transaction taxes, stock-based compensation, the allowance for doubtful accounts, the valuation of goodwill, long-lived assets and intangibles, income taxes, the accrual for loyalty programs and the valuation of redeemable noncontrolling interests.

	Fair Value of Financial Instruments — The Company's financial instruments, including cash, restricted cash, accounts receivable, accounts payable, accrued expenses and deferred merchant bookings, are carried at cost which approximates their fair value because of the short-term nature of these financial instruments. See Notes 4, 5, 11 and 13 for information on fair value for investments, derivatives, the Company's outstanding Senior Notes and redeemable noncontrolling interests.

	Cash and Cash Equivalents — Cash and cash equivalents consists primarily of cash and highly liquid investment grade securities with an original maturity of three months or less.

	Restricted Cash — Restricted cash at December 31, 2014 and 2013 collateralizes office leases and supplier obligations.

	Investments — The Company has classified its investments as available-for-sale securities. These securities are carried at estimated fair value with the aggregate unrealized gains and losses related to these investments, net of taxes, reflected as a part of "Accumulated other comprehensive income (loss)" within stockholders' equity.

	The fair value of the investments is based on the specific quoted market price of the securities or comparable securities at the balance sheet dates. Investments in debt securities are considered to be impaired when a decline in fair value is judged to be other than temporary because the Company either intends to sell or it is more-likely-than not that it will have to sell the impaired security before recovery. Once a decline in fair value is determined to be other than temporary, an impairment charge is recorded and a new cost basis in the investment is established. If the Company does not intend to sell the debt security, but it is probable that the Company will not collect all amounts due, then only the impairment due to the credit risk would be recognized in earnings and the remaining amount of the impairment would be recognized in "Accumulated other comprehensive income (loss)" within stockholders' equity. Marketable securities are presented as current assets on the Company's Consolidated Balance Sheets if they are available to meet the short-term working capital needs of the Company. See Notes 4 and 5 for further detail of investments.

	Property and Equipment — Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization of property and equipment is computed on a straight-line basis over the estimated useful lives of the assets or, when applicable, the life of the lease, whichever is shorter.

	Website and Software Capitalization — Certain direct development costs associated with website and internal-use software are capitalized and include external direct costs of services and payroll costs for employees devoting time to the software projects principally related to website and mobile app development, including support systems, software coding, designing system interfaces and installation and testing of the software. These costs are recorded as property and equipment and are generally amortized over a period of two to five years beginning when the asset is substantially ready for use. Costs incurred for enhancements that are expected to result in additional features or functionality are capitalized and amortized over the estimated useful life of the enhancements. Costs incurred during the preliminary project stage, as well as maintenance and training costs, are expensed as incurred.

	Goodwill — The Company accounts for acquired businesses using the purchase method of accounting which requires that the assets acquired and liabilities assumed be recorded at the date of acquisition at their respective fair values. Any excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. The Company's Consolidated Financial Statements reflect an acquired business starting at the date of the acquisition.

	Goodwill is not subject to amortization and is reviewed at least annually for impairment, or earlier if an event occurs or circumstances change and there is an indication of impairment. The Company tests goodwill at a reporting unit level. The fair value of the reporting unit is compared to its carrying value, including goodwill. Fair values are determined based on discounted cash flows, market multiples or appraised values and are based on market participant assumptions. An impairment is recorded to the extent that the implied fair value of goodwill is less than the carrying value of goodwill. See Note 9 for further information.

	Impairment of Long-Lived Assets and Intangible Assets — The Company reviews long-lived assets and amortizable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. The assessment of possible impairment is based upon the Company's ability to recover the carrying value of the assets from the estimated undiscounted future net cash flows, before interest and taxes, of the related operations. The amount of impairment loss, if any, is measured as the excess of the carrying value of the asset over the present value of estimated future cash flows, using a discount rate commensurate with the risks involved and based on assumptions representative of market participants.

	Agency Revenues

	Agency revenues are derived from travel-related transactions where the Company is not the merchant of record and where the prices of the services sold are determined by third parties. Agency revenues include travel commissions, global distribution system ("GDS") reservation booking fees and customer processing fees, and are reported at the net amounts received, without any associated cost of revenue. Such revenues are generally recognized by the Company when the customers complete their travel.

	Merchant Revenues and Cost of Merchant Revenues

	Merchant revenues and related cost of revenues are derived from services where the Company is the merchant of record and therefore charges the customer's credit card and subsequently pays the travel service provider for the services provided.

	Opaque Services: The Company describes its priceline.com Name Your Own Price® and Express Deals® travel services as "opaque" because certain elements of the service, including the identity of the travel service provider, are not disclosed to the consumer prior to making a reservation. The Name Your Own Price® service connects consumers that are willing to accept a level of flexibility regarding their travel itinerary with travel service providers that are willing to accept a lower price in order to sell their excess capacity without disrupting their existing distribution channels or retail pricing structures. The Company's Name Your Own Price® services use a unique pricing system that allows consumers to "bid" the price they are prepared to pay when submitting an offer for a particular leisure travel service. The Company accesses databases in which participating travel service providers file secure discounted rates, not generally available to the public, to determine whether it can fulfill the consumer's offer. The Company selects the travel service provider and determines the price it will accept from the consumer. Merchant revenues and cost of revenues include the selling price and cost, respectively, of the Name Your Own Price® travel services and are reported on a gross basis.



	In 2012, the Company launched Express Deals® as a merchant semi-opaque hotel reservation service at priceline.com. The Company has since expanded the Express Deals®service to include rental car and air reservation services. Express Deals® allows consumers to select hotel, car and air reservations with price and certain information regarding amenities disclosed prior to making the reservation. The identity of the travel service provider is not known prior to committing to the non-refundable reservation. The Company records the difference between the reservation price to the consumer and the travel service provider cost to the Company of its merchant Express Deals® reservation services on a net basis in merchant revenue.

	The Company recognizes revenues and costs for these services when it confirms the customer's non-refundable offer. In very limited circumstances, the Company makes certain customer concessions to satisfy disputes and complaints. The Company accrues for such estimated losses and classifies the resulting expense as adjustments to merchant revenue and cost of merchant revenues.

	Merchant Retail Services: Merchant revenues for the Company's merchant retail services are derived from transactions where consumers book accommodation reservations or rental car reservations from travel service providers at disclosed rates which are subject to contractual arrangements. Charges are billed to consumers by the Company at the time of booking and are included in deferred merchant bookings until the consumer completes the accommodation stay or returns the rental car. Such amounts are generally refundable upon cancellation, subject to cancellation penalties in certain cases. Merchant revenues and accounts payable to the travel service provider are recognized at the conclusion of the consumer's stay at the accommodation or return of the rental car. The Company records the difference between the reservation price to the consumer and the travel service provider cost to the Company of its merchant retail reservation services on a net basis in merchant revenue.

	Pursuant to the terms of the Company's opaque and retail merchant services, its travel service providers are permitted to bill the Company for the underlying cost of the service during a specified period of time. In the event that the Company is not billed by the travel provider within the specified time period, the Company reduces its cost of revenues by the unbilled amounts.

	Advertising and Other Revenues

	Advertising and other revenues are primarily earned by KAYAK and OpenTable. KAYAK earns advertising revenue primarily by sending referrals to travel service providers and OTAs and from advertising placements on its websites and mobile applications. Generally, revenue related to referrals is earned based upon the completion of travel by a consumer or when a consumer clicks on a referral placement and revenue for advertising placements is earned based upon when a customer clicks on an advertisement or when the Company displays an advertisement. OpenTable earns revenue primarily by facilitating reservations and providing computerized host-stand operations to restaurants through proprietary restaurant management reservation services. The Company recognizes other revenues related to OpenTable for reservation revenues when diners are seated and for subscription revenues on a straight-line basis during the contractual period over which the service is delivered. Revenues are recorded net of redeemable dining points issued to diners during each period presented.

	Loyalty Programs

	The Company provides various loyalty programs. Participating customers earn loyalty points on current transactions that can be redeemed for future qualifying transactions. When the points are earned, the Company estimates the amount of loyalty points expected to be redeemed and records a reduction in revenue. As of December 31, 2014, a liability of $71.1 million for loyalty points programs is included in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheet.

	Tax Recovery Charge, Occupancy Taxes and State and Local Taxes

	The Company provides an online travel service to facilitate online travel purchases by consumers from travel service providers, including accommodation, rental car and airline ticket reservations, and sometimes as part of a vacation package reservation. For merchant model transactions, the Company charges the consumer an amount intended to cover the taxes that the Company anticipates the travel service provider will owe and remit to the local taxing authorities ("tax recovery charge"). Tax rate information for calculating the tax recovery charge is provided to the Company by the travel service providers.

	In certain taxing jurisdictions, the Company is required by passage of a new statute or by court order to collect and remit certain taxes (local occupancy tax, general excise and/or sales tax) imposed upon its margin and/or service fee, or in the case of Hawaii, on the full amount collected from the consumer. In those jurisdictions, the Company is collecting and remitting tax as required. The tax recovery charge and occupancy and other related taxes collected from customers and remitted to those jurisdictions are reported on a net basis on the Consolidated Statement of Operations. Except in those jurisdictions, the Company does not charge the customer or remit occupancy or other related taxes based on its margin or service fee, because the Company believes that such taxes are not owed on its compensation for its services (see Note 16).

	Advertising - Online — Online advertising expenses consist primarily of the costs of (1) search engine keyword purchases; (2) referrals from meta-search and travel research websites; (3) affiliate programs; and (4) banner, pop-up and other Internet and mobile advertisements. Online advertising expense is generally recognized as incurred. Included in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheets are accrued online advertising liabilities of $164.0 million and $130.3 million at December 31, 2014 and 2013, respectively.

	Advertising - Offline — Offline advertising expenses are primarily related to the Company's Booking.com, KAYAK and priceline.com businesses and primarily consist of television advertising. The Company expenses advertising production costs the first time the advertising is broadcast.

Sales and Marketing — Sales and marketing expenses consist primarily of (1) credit card processing fees associated with merchant transactions; (2) fees paid to third parties that provide call center, website content translations and other services; (3) provisions for credit card chargebacks; and (4) provisions for bad debt, primarily related to agency accommodation commission receivables.

Personnel — Personnel expenses consist of compensation to the Company's personnel, including salaries, bonuses, stock-based compensation, payroll taxes and employee health benefits. Included in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheets are accrued compensation liabilities of $159.0 million and $142.7 million at December 31, 2014 and 2013, respectively.

Stock-Based Compensation — The cost of stock-based compensatory transactions is recognized in the financial statements based upon fair value. The fair value of performance share units and restricted stock units is determined based on the number of units or shares, as applicable, granted and the quoted price of the Company's common stock as of the grant date or acquisition date. Stock-based compensation related to performance share units reflects the estimated probable outcome at the end of the performance period. The fair value of employee stock options assumed in acquisitions was determined using the Black Scholes model and the market value of the Company's common stock at the respective acquisition dates. Fair value is recognized as expense on a straight line basis, net of estimated forfeitures, over the employee requisite service period.

The benefits of tax deductions in excess of recognized compensation costs are reported as a credit to additional paid-in capital and as financing cash flows, but only when such excess tax benefits are realized by a reduction to current taxes payable. See Note 3 for further information on stock-based awards.

Information Technology — Information technology expenses consist primarily of: (1) software license and system maintenance fees; (2) data communications and other expenses associated with operating our services; (3) outsourced data center costs; and (4) payments to outside consultants.

Income Taxes — The Company accounts for income taxes under the asset and liability method. The Company records the estimated future tax effects of temporary differences between the tax bases of assets and liabilities and amounts reported on the Consolidated Balance Sheets, as well as operating loss and tax credit carryforwards. Deferred taxes are classified as current or noncurrent based on the balance sheet classification of the related assets and liabilities.

The Company records deferred tax assets to the extent it believes these assets will more likely than not be realized. The Company regularly reviews its deferred tax assets for recoverability considering historical profitability, projected future taxable income, the expected timing of the reversals of existing temporary differences, the carryforward periods available for tax reporting purposes, and tax planning strategies. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The ultimate realization of deferred tax assets depends on the generation of future taxable income during the period in which related temporary differences become deductible. In determining the future tax consequences of events that have been recognized in the financial statements or tax returns, significant judgments, estimates, and interpretation of statutes are required.

Deferred taxes are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date of such change.

Income taxes are not accrued for unremitted earnings of international operations that have been or are intended to be reinvested indefinitely.

The Company recognizes liabilities when it believes that uncertain positions may not be fully sustained upon review by the tax authorities. Liabilities recognized for uncertain tax positions are based on a two step approach for recognition and measurement. First, the Company evaluates the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained on audit based on its technical merits. Secondly, the Company measures the tax benefit as the largest amount which is more than 50% likely of being realized upon ultimate settlement. Interest and penalties attributable to uncertain tax positions, if any, are recognized as a component of income tax expense. See Note 15 for further details on income taxes.

Segment Reporting — The Company determined that its brands constitute its operating segments. Based on similar economics characteristics and other similar operating factors, the Company has aggregated the operating segments into one reportable segment. The Company manages its business as one unit. For geographic related information, see Note 18.

Foreign Currency Translation — The functional currency of the Company's foreign subsidiaries is generally their respective local currency. Assets and liabilities are translated into U.S. Dollars at the rate of exchange existing at the balance sheet date. Income statement amounts are translated at average monthly exchange rates applicable for the period. Translation gains and losses are included as a component of "Accumulated other comprehensive income (loss)" on the Company's Consolidated Balance Sheets. Foreign currency transaction gains and losses are included in "Foreign currency transactions and other" in the Company's Consolidated Statements of Operations.

In September 2014, the Company issued Senior Notes due September 23, 2024 for an aggregate principal amount of 1.0 billion Euros and designated the carrying value, plus accrued interest, as a hedge of the Company's net investment in a Euro functional currency subsidiary. The foreign currency transaction gains or losses on these liabilities and the Euro denominated net assets of the subsidiary are translated into U.S. Dollars and are included as a component of "Accumulated other comprehensive income (loss)" on the Company's Consolidated Balance Sheet (see Notes 11 and 14).
Derivative Financial Instruments — As a result of the Company's international operations, it is exposed to various market risks that may affect its consolidated results of operations, cash flow and financial position. These market risks include, but are not limited to, fluctuations in currency exchange rates. The Company's primary foreign currency exposures are in Euros and British Pound Sterling, in which it conducts a significant portion of its business activities. As a result, the Company faces exposure to adverse movements in currency exchange rates as the financial results of its international operations are translated from local currency into U.S. Dollars upon consolidation. Additionally, foreign exchange rate fluctuations on transactions denominated in currencies other than the functional currency result in gains and losses that are reflected in income.

The Company may enter into derivative instruments to hedge certain net exposures of nonfunctional currency denominated assets and liabilities and the volatility associated with translating earnings for its international businesses into U.S. Dollars, even though it does not elect to apply hedge accounting or hedge accounting does not apply. Gains and losses resulting from a change in fair value for these derivatives are reflected in income in the period in which the change occurs and are recognized on the Consolidated Statements of Operations in "Foreign currency transactions and other." Cash flows related to these contracts are classified within "Net cash provided by operating activities" on the cash flow statement.

The Company, from time to time, utilizes derivative instruments to hedge the impact of changes in currency exchange rates on the net assets of its foreign subsidiaries. These instruments are designated as net investment hedges. Hedge ineffectiveness is assessed and measured based on changes in forward exchange rates. The Company records gains and losses on these derivative instruments as currency translation adjustments, which offset a portion of the translation adjustments related to the foreign subsidiary's net assets. Gains and losses are recognized on the Consolidated Balance Sheet in "Accumulated other comprehensive income (loss)" and will be realized upon a partial sale or liquidation of the investment. The Company formally documents all derivatives designated as hedging instruments for accounting purposes, both at hedge inception and on an on-going basis. These net investment hedges expose the Company to liquidity risk as the derivatives have an immediate cash flow impact upon maturity, which is not offset by the translation of the underlying hedged equity. The cash flows from these contracts are classified within "Net cash used in investing activities" on the cash flow statement.

The Company does not use financial instruments for trading or speculative purposes. The Company recognizes all derivative instruments on the balance sheet at fair value and its derivative instruments are generally short-term in duration. The derivative instruments do not contain leverage features.

The Company is exposed to the risk that counterparties to derivative contracts may fail to meet their contractual obligations. The Company regularly reviews its credit exposure as well as assessing the creditworthiness of its counterparties. See Note 5 for further detail on derivatives.

Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board ("FASB") and the International Accounting Standards Board ("IASB") issued a new accounting standard on the recognition of revenue from contracts with customers that is designed to create greater comparability for financial statement users across industries and jurisdictions. The core principle of the standard is that an "entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services." Additionally, the new guidance specifies the accounting for some costs to obtain or fulfill a contract with a customer. The new standard will also require enhanced disclosures. The accounting standard is effective for public entities for annual and interim periods beginning after December 15, 2016. Early adoption is not permitted under U.S. GAAP and retrospective application is permitted but not required. The Company is currently evaluating the impact on its consolidated financial statements of adopting this new guidance.
In April 2014, the FASB issued an accounting update which amends the definition of a discontinued operation. The new definition limits discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have or will have a major effect on an entity's operations and financial results. The new definition includes an acquired business that is classified as held for sale at the date of acquisition. The accounting update requires new disclosures of both discontinued operations and a disposal of an individually significant component of an entity. The accounting update is effective for annual and interim periods beginning on or after December 15, 2014. Early adoption is permitted but only for disposals that have not been reported in financial statements previously issued. The Company adopted this update in the first quarter of 2015 and this accounting update did not have an impact on the Company's consolidated financial statements.
In July 2013, the FASB issued an accounting update which provides guidance on financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward or a tax credit carryforward exists in the same taxing jurisdiction. Per this guidance, an entity must present the unrecognized tax benefit as a reduction to a deferred tax asset, except when the carryforward is not available as of the reporting date under the governing tax law to settle taxes or the entity does not intend to use the deferred tax asset for this purpose. This amendment does not impact the recognition or measurement of uncertain tax positions or the disclosure reconciliation of gross unrecognized tax benefits. The update is effective for public companies beginning after December 15, 2013. The Company adopted this update in the first quarter of 2014 and this accounting update did not have an impact on the Company's consolidated balance sheet.
In February 2013, the FASB issued accounting guidance which requires entities to provide additional information about items reclassified out of accumulated other comprehensive income ("AOCI") to net income. Changes in AOCI balances by component, both before tax and after tax, must be disclosed and significant items reclassified out of AOCI by component must be reported either on the face of the income statement or in a separate footnote to the financial statements. The accounting guidance is effective for public companies for fiscal years, and interim periods within those years, beginning after December 15, 2012. See Note 14 for information on AOCI balances. There were no reclassifications out of AOCI to net income for the years ended December 31, 2014, 2013 and 2012.
On January 1, 2012, the Company adopted the amended accounting guidance issued by the Financial Accounting Standards Board ("FASB") concerning the presentation of comprehensive income. The new guidance requires comprehensive income to be reported in either a single statement or in two consecutive statements reporting net income and other comprehensive income. The Company selected to present two consecutive statements. This amended guidance did not change the items that constitute net income or other comprehensive income, the timing of when other comprehensive income is reclassified to net income, or the earnings per share computation.

In September 2011, the FASB issued an accounting update, which amended the guidance on testing goodwill for impairment. Under the revised guidance, entities testing goodwill for impairment have the option of performing a qualitative assessment before calculating the fair value of the reporting unit. If, based on the qualitative factors, it is more-likely-than not that the fair value of the reporting unit is less than its carrying value, then the unchanged two-step approach previously used would be required. The new accounting guidance did not change how goodwill is calculated, how goodwill is assigned to the reporting unit, or the requirements for testing goodwill annually or when events and circumstances warrant testing. The accounting update was effective for annual and interim periods beginning after December 15, 2011, with early adoption permitted. In September 2014, the Company performed its annual quantitative goodwill impairment testing and concluded that there was no impairment of goodwill.

In May 2010, the FASB issued amended guidance on fair value to largely achieve common fair value measurement and disclosure requirements between U.S. GAAP and IFRS. The new accounting guidance did not extend the use of fair value but rather provided guidance about how fair value should be determined. For U.S. GAAP, most of the changes were clarifications of existing guidance or wording changes to align with IFRS. The amended guidance expanded disclosure, particularly that relating to fair value measurements based on unobservable inputs, permitted fair value measurements for financial assets and liabilities on a net position if market or credit risks are managed on a net basis and other criteria are met, and allowed premiums and discounts only if a market participant would also include them in the fair value measurement. This accounting update was effective for public companies for interim or annual periods beginning after December 15, 2011, with early adoption permitted. The adoption of this accounting guidance, effective with the three months ended March 31, 2012, did not impact the Company's consolidated financial statements or disclosure.

STOCKBASED_COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION

	The Company's 1999 Omnibus Plan, as amended and restated effective June 6, 2013, (the "1999 Plan") is the primary stock compensation plan from which broad-based employee equity awards may be made. As of December 31, 2014, there were 2,650,485 shares of common stock available for future grant under the 1999 Plan. In addition, in connection with the acquisition of KAYAK in May 2013, Buuteeq, Inc. in June 2014 and OpenTable in July 2014, the Company assumed the KAYAK Software Corporation 2012 Equity Incentive Plan (the "KAYAK Plan"), the Buuteeq, Inc. Amended and Restated 2010 Stock Plan (the "Buuteeq Plan") and the OpenTable, Inc. 2009 Equity Incentive Award Plan (the "OpenTable Plan"). As of December 31, 2014, there were 14,351, 191 and 238,804 shares of common stock available for future grant under the KAYAK Plan, Buuteeq Plan and OpenTable Plan, respectively.

	Stock-based compensation issued under the plans generally consists of restricted stock units, performance share units and stock options. The cost of share-based transactions is recognized in the financial statements based upon fair value. Fair value is recognized as expense on a straight line basis, net of estimated forfeitures, over the employee's requisite service period. The fair value of restricted stock units and performance share units is determined based on the number of shares or units, as applicable, granted and the quoted price of the Company's common stock as of the grant date. Stock-based compensation related to performance share units reflects the estimated probable outcome at the end of the performance period. The fair value of the employee stock options assumed in acquisitions was determined using the Black-Scholes model and the market value of the Company's common stock at the respective merger date. Stock options granted to employees have a term of 10 years. Restricted stock units, performance share units and restricted stock generally vest over periods from 1 to 4 years. The Company issues new shares of common stock upon the issuance of restricted stock, the exercise of stock options and the vesting of restricted stock units and performance share units.

	Stock-based compensation included in personnel expenses in the Consolidated Statements of Operations was approximately $186.4 million, $140.5 million and $71.6 million for the years ended December 31, 2014, 2013 and 2012, respectively. Stock-based compensation for the years ended December 31, 2014, 2013 and 2012 includes charges amounting to $20.6 million, $24.1 million and $0.9 million, respectively, representing the impact of adjusting the estimated probable outcome at the end of the performance period for outstanding unvested performance share units. Included in the stock-based compensation are approximately $2.3 million, $2.1 million, and $1.8 million for the years ended December 31, 2014, 2013, and 2012, respectively, for grants to non-employee directors. The related tax benefit for stock-based compensation is $38.4 million, $18.5 million and $7.6 million for the years ended December 31, 2014, 2013 and 2012, respectively.

	Restricted Stock Units and Performance Share Units

	The following table summarizes the activity of unvested restricted stock units ("RSUs") and performance share units during the years ended December 31, 2012, 2013 and 2014:



	Share-Based Awards	Shares		Weighted Average Grant
				Date Fair Value

	Unvested at December 31, 2011	799,980			$	231.87


	Granted	95,062			$	643.12

	Vested	(353,819	)		$	108.31

	Performance Shares Adjustment	6,649			$	532.26

	Forfeited	(7,744	)		$	444.18

	Unvested at December 31, 2012	540,128			$	389.21


	Granted	162,341			$	730.47

	Vested	(258,198	)		$	242.63

	Performance Shares Adjustment	101,490			$	681.13

	Forfeited	(11,442	)		$	579.71

	Unvested at December 31, 2013	534,319			$	615.1


	Granted	128,484			$	1,308.13

	Assumed in an acquisition	43,993			$	1,238.68

	Vested	(195,730	)		$	492.22

	Performance Shares Adjustment	68,499			$	1,085.94

	Forfeited	(9,250	)		$	972.19

	Unvested at December 31, 2014	570,315			$	912.26


	RSUs and performance share units granted by the Company during the years ended December 31, 2014, 2013 and 2012 had aggregate grant date fair values of approximately $168.1 million, $118.6 million and $61.1 million, respectively. Share-based awards that vested during the years ended December 31, 2014, 2013, and 2012 had grant date fair values of $96.3 million, $62.6 million and $38.3 million, respectively.

	As of December 31, 2014, there is $263.8 million of total future compensation cost related to unvested share-based awards to be recognized over a weighted-average period of 1.7 years.

	During the year ended December 31, 2014, stock based awards included grants of 72,277 performance share units to executives and certain other employees. The performance share units had a total grant date fair value of $96.1 million based upon the weighted-average grant date fair value per share of $1,329.11. The performance share units are payable in shares of the Company's common stock upon vesting. Stock-based compensation for performance share units is recorded based on the estimated probable outcome if the Company, and with respect to certain grants, the businesses of its subsidiaries, achieve certain financial goals at the end of the performance period. The actual number of shares to be issued on the vesting date will be determined upon completion of the performance period which ends December 31, 2016, assuming there is no accelerated vesting for, among other things, a termination of employment under certain circumstances, or a change in control. At December 31, 2014, there were 72,098 unvested 2014 performance share units outstanding, net of performance share units that were forfeited or vested since the grant date. As of December 31, 2014, the number of shares estimated to be issued pursuant to these performance shares units is a total of 109,618 shares. If the maximum performance thresholds are met at the end of the performance period, a maximum of 145,981 total shares could be issued. If the minimum performance thresholds are not met, 50,884 shares would be issued at the end of the performance period.

	2013 Performance Share Units

	During the year ended December 31, 2013, stock-based awards included grants of 104,865 performance share units with a grant date fair value of $74.4 million, based on a weighted average grant date fair value of $709.74 per share. The actual number of shares will be determined upon completion of the performance period which ends December 31, 2015.

At December 31, 2014, there were 102,816 unvested 2013 performance share units outstanding, net of performance share units that were forfeited or vested since the grant date. As of December 31, 2014, the number of shares estimated to be issued pursuant to these performance share units at the end of the performance period is a total of 197,225 shares. If the maximum performance thresholds are met at the end of the performance period, a maximum of 225,202 total shares could be issued pursuant to these performance share units. If the minimum performance thresholds are not met, 40,120 shares would be issued at the end of the performance period.

2012 Performance Share Units

During the year ended December 31, 2012, stock-based awards included grants of 60,365 performance share units with a grant date fair value of $39.0 million, based on a weighted average grant date fair value of $645.86 per share. The actual number of shares will be determined after completion of the performance period which ended on December 31, 2014.

At December 31, 2014, there were 57,571 unvested 2012 performance share units outstanding, net of performance share units that were forfeited or vested since the grant date. As of December 31, 2014, the total number of shares expected to be issued pursuant to these performance shares units on the March 4, 2015 vesting date is 100,190 shares.

Stock Options - Other than Stock Options Assumed in Acquisitions

During the year ended December 31, 2014, stock options were exercised for 7,780 shares of common stock with a weighted average exercise price per share of $22.47. As of December 31, 2014, there were 1,220 shares of common stock subject to outstanding and exercisable stock options with a weighted average exercise price per share of $23.08, a weighted average remaining term of 0.5 years, and an aggregate intrinsic value of $1.4 million. The intrinsic value of stock options exercised during the years ended December 31, 2014, 2013 and 2012 was $9.3 million, $44.9 million and $75.2 million, respectively. As of December 31, 2011, there were no outstanding and unvested stock options originally granted by the Company. No stock options were granted by the Company during the years ended December 31, 2014, 2013 and 2012.

Stock Options Assumed in Acquisitions

The following table summarizes for the year ended December 31, 2014 stock option activity for employee stock options assumed in acquisitions:


Assumed Employee Stock Options		Number of Shares			Weighted Average			Aggregate			Weighted Average Remaining Contractual Term (in years)
					Exercise Price			Intrinsic Value (000's)
Balance, January 1, 2013		—				$	—		$	—	0

Assumed in acquisition		540,179				$	260.96

Exercised		(387,669	)			$	222.73

Forfeited		(23,802	)			$	478.83

Balance, December 31, 2013		128,708				$	335.83		$	106,386	6.9

Assumed in acquisitions		61,897				$	457.67

Exercised		(43,223	)			$	342.39

Forfeited		(2,217	)			$	517.91

Balance, December 31, 2014		145,165				$	383.05		$	109,914	6.5

Vested and exercisable as of December 31, 2014		88,118				$	306.32		$	73,481	5.7

Vested and exercisable as of December 31, 2014 and expected to vest thereafter, net of estimated forfeitures		144,077				$	382.81		$	109,124	6.5


The aggregate intrinsic value of exercised employee stock options assumed in acquisitions during the years ended December 31, 2014 and 2013 was $39.9 million and $236.9 million, respectively.

For the year ended December 31, 2014, employee stock options assumed in acquisitions had a total acquisition date fair value of $45.5 million based on a weighted average acquisition date fair value of $734.76 per share. During the year ended December 31, 2014 and 2013, assumed unvested employee stock options vested for 41,524 and 65,293 shares with a fair value of $24.2 million and $30.9 million, respectively.

For the year ended December 31, 2014 and 2013, the Company recorded stock-based compensation expense of $24.7 million and $30.9 million, respectively related to unvested assumed employee stock options. As of December 31, 2014, there was $36.2 million of total future compensation costs related to unvested assumed employee stock options to be recognized over a weighted-average period of 1.6 years.

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS

	The following table summarizes, by major security type, the Company's investments as of December 31, 2014 (in thousands):



		Cost		Gross		Gross			Fair Value
				Unrealized		Unrealized
				Gains		Losses
	Available for sale securities:
	Short-term investments:
	Foreign government securities	$	52,524	$	—	$	(34	)	$	52,490

	U.S. government securities	364,276		24		(34		)	364,266

	U.S. commercial paper	621,252		15		(652		)	620,615

	U.S. government agency securities	104,829		—		(18		)	104,811

	Total short-term investments	$	1,142,881	$	39	$	(738	)	$	1,142,182


	Long-term investments:
	Foreign government securities	$	12,707	$	—	$	(36	)	$	12,671

	U.S. government securities	557,130		80		(762		)	556,448

	U.S. corporate debt securities	2,332,030		2,299		(5,296		)	2,329,033

	U.S. government agency securities	95,108		97		(111		)	95,094

	U.S. municipal securities	1,114		—		(12		)	1,102

	Ctrip corporate debt securities	500,000		—		(74,039		)	425,961

	Ctrip equity securities	421,930		—		(86,586		)	335,344

	Total long-term investments	$	3,920,019	$	2,476	$	(166,842	)	$	3,755,653


	As of December 31, 2014, foreign government securities included investments in debt securities issued by the governments of the United Kingdom and the Netherlands.

	In August 2014, the Company used its non-U.S. cash to invest in a five-year Senior Convertible Note issued by Ctrip.com International Ltd. ("Ctrip"). The note was issued at par in an aggregate principal amount of $500 million. Additionally, during the year ended December 31, 2014, the Company invested $421.9 million of its non-U.S. cash in Ctrip American Depositary Shares ("ADSs"). The convertible debt and equity securities of Ctrip have been marked to market in accordance with the accounting guidance for available-for-sale securities and at December 31, 2014 show a $74.0 million and $86.6 million unrealized loss, respectively, as a result of decreases in Ctrip's publicly traded shares since the convertible debt and equity purchases were made. In connection with the purchase of the convertible note, Ctrip granted the Company the right to appoint an observer to Ctrip's board of directors and permission to acquire Ctrip shares (including through the acquisition of Ctrip ADSs in the open market) over the twelve months following the purchase date, so that combined with ADSs issuable upon conversion of the note, the Company may hold up to 10% of Ctrip's outstanding equity.

	The following table summarizes, by major security type, the Company's short-term investments as of December 31, 2013 (in thousands):



		Cost		Gross		Gross			Fair Value
				Unrealized		Unrealized
				Gains		Losses
	Available for sale securities:
	Short-term investments:
	Foreign government securities	$	4,019,530	$	233	$	(356	)	$	4,019,407

	U.S. government securities	1,443,083		250		(20		)	1,443,313

	Total	$	5,462,613	$	483	$	(376	)	$	5,462,720


	The Company has classified its investments as available-for-sale securities. These securities are carried at estimated fair value with the aggregate unrealized gains and losses related to these investments, net of taxes, reflected as a part of "Accumulated other comprehensive income (loss)" on the Consolidated Balance Sheets. Classification as short-term or long-term is based upon the maturity of the debt securities.

	There were no significant realized gains or losses related to investments for the years ended December 31, 2014, 2013 and 2012.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS

	Financial assets and liabilities are carried at fair value as of December 31, 2014 and are classified in the categories described in the tables below (in thousands):



			Level 1			Level 2			Total
	ASSETS:
	Cash equivalents:
	Money market funds		$	155,608		$	—		$	155,608

	Foreign government securities		—			974,855			974,855

	U.S. government securities		—			676,503			676,503

	U.S. commercial paper		—			427,884			427,884

	U.S. government agency securities		—			10,000			10,000

	Short-term investments:
	Foreign government securities		—			52,490			52,490

	U.S. government securities		—			364,266			364,266

	U.S. commercial paper		—			620,615			620,615

	U.S. government agency securities		—			104,811			104,811

	Foreign exchange derivatives		—			336			336

	Long-term investments:
	Foreign government securities		—			12,671			12,671

	U.S. government securities		—			556,448			556,448

	U.S. corporate debt securities		—			2,329,033			2,329,033

	U.S. government agency securities		—			95,094			95,094

	U.S. municipal securities		—			1,102			1,102

	Ctrip corporate debt securities		—			425,961			425,961

	Ctrip equity securities		335,344			—			335,344

	Total assets at fair value		$	490,952		$	6,652,069		$	7,143,021




			Level 1			Level 2			Total
	LIABILITIES:
	Foreign exchange derivatives		$	—		$	129		$	129


	Financial assets and liabilities are carried at fair value as of December 31, 2013 and are classified in the categories described in the tables below (in thousands):



			Level 1			Level 2			Total
	ASSETS:

	Cash equivalents:
	Money market funds		$	433,850		$	—		$	433,850

Foreign government securities		—			238,202			238,202

U.S. government securities		—			28,000			28,000

Short-term investments:

Foreign government securities		—			4,019,407			4,019,407

U.S. government securities		—			1,443,313			1,443,313

Foreign exchange derivatives		—			292			292

Total assets at fair value		$	433,850		$	5,729,214		$	6,163,064




		Level 1			Level 2			Total
LIABILITIES:

Foreign exchange derivatives		$	—		$	122,091		$	122,091



There are three levels of inputs to measure fair value. The definition of each input is described below:


Level 1:	Quoted prices in active markets that are accessible by the Company at the measurement date for identical assets and liabilities.


Level 2:	Inputs are observable, either directly or indirectly. Such prices may be based upon quoted prices for identical or comparable securities in active markets or inputs not quoted on active markets, but corroborated by market data.


Level 3:	Unobservable inputs are used when little or no market data is available.

Investments in corporate debt securities, sovereign debt, commercial paper, government agency securities and municipal securities are considered "Level 2" valuations because the Company has access to quoted prices, but does not have visibility to the volume and frequency of trading for all of these investments. For the Company's investments, a market approach is used for recurring fair value measurements and the valuation techniques use inputs that are observable, or can be corroborated by observable data, in an active marketplace.

The Company's derivative instruments are valued using pricing models. Pricing models take into account the contract terms as well as multiple inputs where applicable, such as interest rate yield curves, option volatility and currency rates. Derivatives are considered "Level 2" fair value measurements. The Company's derivative instruments are typically short-term in nature.

As of December 31, 2014 and 2013, the Company's cash consisted of bank deposits and cash held in investment accounts. Other financial assets and liabilities, including restricted cash, accounts receivable, accounts payable, accrued expenses and deferred merchant bookings are carried at cost which approximates their fair value because of the short-term nature of these items. See Note 4 for information on the carrying value of investments and Note 11 for the estimated fair value of the Company's Senior Convertible Notes.

In the normal course of business, the Company is exposed to the impact of foreign currency fluctuations. The Company limits these risks by following established risk management policies and procedures, including the use of derivatives. See Note 2 for further information on our accounting policy for derivative financial instruments.

Derivatives Not Designated as Hedging Instruments — The Company is exposed to adverse movements in currency exchange rates as the operating results of its international operations are translated from local currency into U.S. Dollars upon consolidation. The Company's derivative contracts principally address short-term foreign exchange fluctuations for the Euro and British Pound Sterling versus the U.S. Dollar. As of December 31, 2014 and 2013, there were no outstanding derivative contracts related to foreign currency translation risk. Foreign exchange gains of $13.7 million, $0.3 million and $0.7 million for the years ended December 31, 2014, 2013 and 2012, respectively, were recorded related to these derivatives in "Foreign currency transactions and other" in the Consolidated Statements of Operations.

The Company also enters into foreign currency forward contracts to hedge its exposure to the impact of movements in currency exchange rates on its transactional balances denominated in currencies other than the functional currency. Foreign exchange derivatives outstanding as of December 31, 2014 associated with foreign currency transaction risks resulted in a net asset of $0.2 million, with an asset in the amount of $0.3 million recorded in "Prepaid expenses and other current assets" and a liability in the amount of $0.1 million recorded in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheet. Foreign exchange derivatives outstanding at December 31, 2013 associated with foreign exchange transaction risks resulted in a net liability of $0.5 million, with a liability in the amount of $0.6 million recorded in "Accrued expenses and other current liabilities" and an asset in the amount of $0.1 million recorded in "Prepaid and other current assets" on the Consolidated Balance Sheet. Derivatives associated with these transaction risks resulted in foreign exchange losses of $21.8 million compared to foreign exchange gains of $3.6 million and $0.8 million for the years ended December 31, 2014, 2013 and 2012, respectively. These mark-to-market adjustments on the derivative contracts, offset by the effect of changes in currency exchange rates on transactions denominated in currencies other than the functional currency, resulted in net losses of $11.8 million, $5.5 million and $5.5 million for the years ended December 31, 2014, 2013 and 2012, respectively. These net impacts are reported in “Foreign currency transactions and other” on the Consolidated Statements of Operations.

The settlement of derivative contracts not designated as hedging instruments for the year ended December 31, 2014 resulted in a net cash outflow of $8.9 million, compared to net cash inflows of $4.4 million and $1.9 million for the years ended December 31, 2013 and 2012, respectively, and were reported within "Net cash provided by operating activities" on the Consolidated Statements of Cash Flows.

Derivatives Designated as Hedging Instruments — The Company had no foreign currency forward contracts designated as hedges of its net investment in a foreign subsidiary outstanding as of December 31, 2014. As of December 31, 2013, the Company had outstanding foreign currency forward contracts with a notional value of 3.0 billion Euros to hedge a portion of its net investment in a foreign subsidiary. These contracts were all short-term in nature. Hedge ineffectiveness is assessed and measured based on changes in forward exchange rates. The fair value of these derivatives at December 31, 2013 was a net liability of $121.3 million, with a liability in the amount of $121.5 million recorded in "Accrued expenses and other current liabilities" and an asset in the amount of $0.2 million recorded in "Prepaid expenses and other current assets" on the Consolidated Balance Sheet. These hedging instruments generated net cash outflows of $80.3 million and $78.6 million for the years ended December 31, 2014 and 2013, compared to a net cash inflows of $82.1 million for the year ended December 31, 2012, and were reported within "Net cash used in investing activities" on the Consolidated Statements of Cash Flows.

ACCOUNTS_RECEIVABLE_RESERVES

ACCOUNTS RECEIVABLE RESERVES	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
ACCOUNTS RECEIVABLE RESERVES	ACCOUNTS RECEIVABLE RESERVES

	The Company records a provision for uncollectible agency commissions, principally receivables from accommodations related to agency reservations. The Company also accrues for costs associated with merchant transactions made on its websites by individuals using fraudulent credit cards and for other amounts "charged back" as a result of payment disputes. Changes in accounts receivable reserves consisted of the following (in thousands):



		For the Year Ended December 31,
		2014			2013			2012
	Balance, beginning of year	$	14,116		$	10,322		$	6,103

	Provision charged to expense	22,990			16,451			16,094

	Charge-offs and adjustments	(21,546		)	(13,072		)	(11,977		)
	Currency translation adjustments	(1,348		)	415			102

	Balance, end of year	$	14,212		$	14,116		$	10,322

NET_INCOME_PER_SHARE

NET INCOME PER SHARE	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
NET INCOME PER SHARE	NET INCOME PER SHARE

	The Company computes basic net income per share by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per share is based upon the weighted average number of common and common equivalent shares outstanding during the period.

	Common equivalent shares related to stock options, restricted stock, restricted stock units, and performance share units are calculated using the treasury stock method. Performance share units are included in the weighted average common equivalent shares based on the number of shares that would be issued if the end of the reporting period were the end of the performance period, if the result would be dilutive.

	The Company's convertible debt issues have net share settlement features requiring the Company upon conversion to settle the principal amount of the debt for cash and the conversion premium for cash or shares of the Company's common stock at the Company's option. The convertible notes are included in the calculation of diluted net income per share if their inclusion is dilutive under the treasury stock method.

	A reconciliation of the weighted average number of shares outstanding used in calculating diluted earnings per share is as follows (in thousands):



		For the Year Ended December 31,
		2014	2013	2012
	Weighted average number of basic common shares outstanding	52,301	50,924	49,840

	Weighted average dilutive stock options, restricted stock units and performance share units	340	382	501

	Assumed conversion of Convertible Senior Notes	382	1,107	985

	Weighted average number of diluted common and common equivalent shares outstanding	53,023	52,413	51,326

	Anti-dilutive potential common shares	2,574	2,384	2,202


	Anti-dilutive potential common shares for the years ended December 31, 2014, 2013 and 2012 include approximately 2.1 million shares, 2.0 million shares and 2.0 million shares, respectively, that could be issued under the Company's convertible notes if the Company experiences substantial increases in its common stock price. Under the treasury stock method, the convertible notes will generally have a dilutive impact on net income per share if the Company's average stock price for the period exceeds the conversion price for the convertible notes.

	In 2006, the Company issued $172.5 million aggregate principal amount of convertible notes due September 30, 2013 (the "2013 Notes"). In 2006, the Company also entered into hedge transactions (the "Conversion Spread Hedges") relating to the potential dilution of the Company's common stock upon conversion of the 2013 Notes at their stated maturity date. The Conversion Spread Hedges were settled in October 2013 and the Company received 42,160 shares of common stock from the counterparties. The settlement was accounted for as an equity transaction. Since the impact of the Conversion Spread Hedges was anti-dilutive, it was excluded from the calculation of net income per share until the shares of common stock were received in October 2013.

PROPERTY_AND_EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	PROPERTY AND EQUIPMENT

	Property and equipment at December 31, 2014 and 2013 consisted of the following (in thousands):



		2014			2013			Estimated
								Useful Lives
								(years)
	Computer equipment and software	$	332,650		$	244,845		2 to 5

	Office equipment, furniture, fixtures & leasehold improvements	110,297			67,942			2 to 11

	Total	442,947			312,787

	Less: accumulated depreciation and amortization	(243,994		)	(177,734		)
	Property and equipment, net	$	198,953		$	135,053


	Fixed asset depreciation and amortization expense was approximately $78.2 million, $48.4 million and $32.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.

INTANGIBLE_ASSETS_AND_GOODWILL

INTANGIBLE ASSETS AND GOODWILL	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS AND GOODWILL	INTANGIBLE ASSETS AND GOODWILL

	The Company's intangible assets at December 31, 2014 and 2013 consisted of the following (in thousands):



		December 31, 2014									December 31, 2013
		Gross Carrying				Accumulated			Net Carrying		Gross Carrying		Accumulated			Net Carrying		Amortization	Weighted Average Useful
		Amount				Amortization			Amount		Amount		Amortization			Amount		Period	Life

	Supply and distribution agreements	$	842,642			$	(188,441	)	$	654,201	$	581,742	$	(160,499	)	$	421,243	10 - 20 years	16 years


	Technology	108,987				(43,746		)	65,241		93,322		(29,271		)	64,051		1 - 5 years	5 years


	Patents	1,623				(1,524		)	99		1,623		(1,478		)	145		15 years	15 years


	Internet domain names	41,652				(16,895		)	24,757		45,799		(12,112		)	33,687		2 - 20 years	8 years


	Trade names	1,674,218				(100,850		)	1,573,368		548,243		(47,388		)	500,855		5 - 20 years	20 years


	Non-compete agreements	21,000				(3,908		)	17,092		—		—			—		3 years	3 years


	Other	141				(138		)	3		141		(137		)	4		3 - 10 years	3 years

	Total intangible assets	$	2,690,263			$	(355,502	)	$	2,334,761	$	1,270,870	$	(250,885	)	$	1,019,985


	Intangible assets with determinable lives are amortized on a straight-line basis. Intangible assets amortization expense is approximately $129.6 million, $69.6 million and $32.3 million for the years ended December 31, 2014, 2013 and 2012, respectively.

	The annual estimated amortization expense for intangible assets for the next five years and thereafter is expected to be as follows (in thousands):



	2015	$	171,007

	2016	167,887

	2017	160,296

	2018	141,776

	2019	131,727

	Thereafter	1,562,068

		$	2,334,761


	A roll-forward of goodwill for the years ended December 31, 2014 and 2013 consisted of the following (in thousands):



		2014				2013
	Balance, beginning of year	$	1,767,912			$	522,672

	Acquisitions	1,590,829				1,232,342

	Currency translation adjustments	(32,267		)		12,898

Balance, end of year	$	3,326,474			$	1,767,912


A substantial portion of the intangibles and goodwill relates to the acquisition of OpenTable in July 2014 and KAYAK in May 2013. See Note 20 for further information on these acquisitions.

In September 2014, the Company performed its annual goodwill impairment testing using standard valuation techniques. Since the annual impairment test, there have been no events or changes in circumstances to indicate a potential impairment.

OTHER_ASSETS

OTHER ASSETS	12 Months Ended
	Dec. 31, 2014
Investments, All Other Investments [Abstract]
OTHER ASSETS	OTHER ASSETS

	Other assets at December 31, 2014 and 2013 consisted of the following (in thousands):



		2014		2013
	Deferred debt issuance costs	$	27,204	$	16,465

	Security deposits	12,368		10,617

	Deferred tax assets	8,548		7,055

	Other	9,228		6,432

	Total	$	57,348	$	40,569


	Deferred debt issuance costs arose from (i) the $1.0 billion aggregate principal amount of 1.0% Convertible Senior Notes, due March 15, 2018, issued in March 2012; (ii) a $1.0 billion revolving credit facility entered into in October 2011; (iii) the $575.0 million aggregate principal amount of 1.25% Convertible Senior Notes, due March 15, 2015, issued in March 2010; (iv) the $1.0 billion aggregate principal amount of 0.35% Convertible Senior Notes, due June 15, 2020, issued in May 2013; (v) the $1.0 billion aggregate principal amount of 0.9% Convertible Senior Notes, due September 15, 2021, issued in August 2014; and (vi) the 1.0 billion Euro aggregate principal amount of 2.375% Senior Notes, due September 23, 2024, issued in September 2014. Deferred debt issuance costs are being amortized using the effective interest rate method and the period of amortization was determined at inception of the related debt agreements based upon the stated maturity dates. Unamortized debt issuance costs written off to interest expense in the years ended December 31, 2014 and 2013 related to early conversion of convertible debt and amounted to $0.5 million and $2.4 million, respectively.

DEBT

DEBT	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
DEBT	DEBT

	Revolving Credit Facility

	In October 2011, the Company entered into a $1.0 billion five-year unsecured revolving credit facility with a group of lenders. Borrowings under the revolving credit facility will bear interest, at the Company's option, at a rate per annum equal to either (i) the adjusted LIBOR for the interest period in effect for such borrowing plus an applicable margin ranging from 1.00% to 1.50%; or (ii) the greatest of (a) JPMorgan Chase Bank, National Association's prime lending rate, (b) the federal funds rate plus 0.50%, and (c) an adjusted LIBOR for an interest period of one month plus 1.00%, plus an applicable margin ranging from 0.00% to 0.50%. Undrawn balances available under the revolving credit facility are subject to commitment fees at the applicable rate ranging from 0.10% to 0.25%.

	The revolving credit facility provides for the issuance of up to $100.0 million of letters of credit as well as borrowings of up to $50 million on same-day notice, referred to as swingline loans. Borrowings under the revolving credit facility may be made in U.S. Dollars, Euros, British Pounds Sterling and any other foreign currency agreed to by the lenders. The proceeds of loans made under the facility will be used for working capital and general corporate purposes.

	The Company funded the acquisition of OpenTable in July 2014 from cash on hand in the United States and $995 million borrowed under the Company's revolving credit facility, which the Company repaid during the third quarter of 2014. As of December 31, 2014 and 2013, there were no borrowings under the facility, and approximately $4.0 million and $2.2 million, respectively, of letters of credit issued under the facility.

	Outstanding Debt

	Outstanding debt as of December 31, 2014 consisted of the following (in thousands):



	December 31, 2014	Outstanding		Unamortized			Carrying
		Principal		Debt			Value
		Amount		Discount
	Short-term debt:
	1.25% Convertible Senior Notes due March 2015	$	37,524	$	(329	)	$	37,195


	Long-term debt:
	1.0% Convertible Senior Notes due March 2018	$	1,000,000	$	(74,834	)	$	925,166

	0.35% Convertible Senior Notes due June 2020	1,000,000		(138,114		)	861,886

	0.9% Convertible Senior Notes due September 2021	1,000,000		(136,299		)	863,701

	2.375% (€1 Billion) Senior Notes due September 2024	1,210,068		(11,065		)	1,199,003

	Total long-term debt	$	4,210,068	$	(360,312	)	$	3,849,756


	Outstanding debt as of December 31, 2013 consisted of the following (in thousands):



	December 31, 2013	Outstanding		Unamortized			Carrying
		Principal		Debt			Value
		Amount		Discount
	Short-term debt:
	1.25% Convertible Senior Notes due March 2015	$	160,464	$	(8,533	)	$	151,931


	Long-term debt:
	1.0% Convertible Senior Notes due March 2018	$	1,000,000	$	(96,797	)	$	903,203

	0.35% Convertible Senior Notes due June 2020	1,000,000		(161,156		)	838,844

	Total long-term debt	$	2,000,000	$	(257,953	)	$	1,742,047


	Based upon the closing price of the Company's common stock for the prescribed measurement periods during the three months ended December 31, 2013, the contingent conversion threshold on the 2015 Notes (as defined below) was exceeded. The 2015 Notes became convertible on December 15, 2014, at the option of the holders, and will remain convertible until the scheduled trading day immediately preceding the maturity date of March 15, 2015, regardless of the Company's stock price. Therefore, the 2015 Notes were convertible at the option of the holders as of December 31, 2014 and 2013, and accordingly the Company reported the carrying value of the 2015 Notes as a current liability as of December 31, 2014 and 2013. Since these notes are convertible at the option of the holders and the principal amount is required to be paid in cash, the difference between the principal amount and the carrying value is reflected as convertible debt in the mezzanine section on the Company's Consolidated Balance Sheet. Therefore, with respect to the 2015 Notes, the Company reclassified the unamortized debt discount for these 1.25% Notes in the amount of $0.3 million and $8.5 million before tax as of December 31, 2014 and 2013, respectively, from additional paid-in-capital to convertible debt in the mezzanine section on the Company's Consolidated Balance Sheet.

	The contingent conversion thresholds on the 2018 Notes (as defined below), the 2020 Notes (as defined below) and the 2021 Notes (as defined below) were not exceeded at December 31, 2014 or December 31, 2013, and therefore these Notes are reported as a non-current liability on the Consolidated Balance Sheet.

	Fair Value of Debt

	As of December 31, 2014 and 2013, the estimated market value of the outstanding Senior Notes was approximately $4.8 billion and $3.1 billion, respectively, and was considered a "Level 2" fair value measurement (see Note 5). Fair value was estimated based upon actual trades at the end of the reporting period or the most recent trade available as well as the Company's stock price at the end of the reporting period. A substantial portion of the market value of the Company's debt in excess of the outstanding principal amount relates to the conversion premium on the Convertible Senior Notes.

	Convertible Debt

If the note holders exercise their option to convert, the Company is required to deliver cash to repay the principal amount of the notes and may deliver shares of common stock or cash, at its option, to satisfy the conversion value in excess of the principal amount. In cases where holders decide to convert prior to the maturity date, the Company writes off the proportionate amount of remaining debt issuance costs to interest expense. In the year ended December 31, 2014, the Company paid $122.9 million to satisfy the aggregate principal amount due and issued 300,256 shares of its common stock and paid cash of $2.2 million in satisfaction of the conversion value in excess of the principal amount for debt converted prior to maturity. In the year ended December 31, 2013, the Company delivered cash of $414.6 million to repay the principal amount and issued 972,235 shares of its common stock in satisfaction of the conversion value in excess of the principal amount for convertible debt that was converted prior to maturity.

Description of Senior Convertible Notes

In August 2014, the Company issued in a private placement $1.0 billion aggregate principal amount of Convertible Senior Notes due September 15, 2021, with an interest rate of 0.9% (the "2021 Notes"). The Company paid $11.0 million in debt issuance costs during the year ended December 31, 2014, related to this offering. The 2021 Notes are convertible, subject to certain conditions, into the Company's common stock at a conversion price of approximately $2,055.50 per share. The 2021 Notes are convertible, at the option of the holder, prior to September 15, 2021, upon the occurrence of specific events, including but not limited to a change in control, or if the closing sales price of the Company's common stock for at least 20 trading days in the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is more than 150% of the applicable conversion price in effect for the notes on the last trading day of the immediately preceding quarter. In the event that all or substantially all of the Company's common stock is acquired on or prior to the maturity of the 2021 Notes in a transaction in which the consideration paid to holders of the Company's common stock consists of all or substantially all cash, the Company would be required to make additional payments in the form of additional shares of common stock to the holders of the 2021 Notes in an aggregate value ranging from $0 to approximately $375 million depending upon the date of the transaction and the then current stock price of the Company. As of June 15, 2021, holders will have the right to convert all or any portion of the 2021 Notes. The 2021 Notes may not be redeemed by the Company prior to maturity. The holders may require the Company to repurchase the 2021 Notes for cash in certain circumstances. Interest on the 2021 Notes is payable on March 15 and September 15 of each year.

In May 2013, the Company issued in a private placement $1.0 billion aggregate principal amount of Convertible Senior Notes due June 15, 2020, with an interest rate of 0.35% (the "2020 Notes"). The 2020 Notes were issued with an initial discount of $20.0 million. The Company paid $1.0 million in debt issuance costs during the year ended December 31, 2013, related to this offering. The 2020 Notes are convertible, subject to certain conditions, into the Company's common stock at a conversion price of approximately $1,315.10 per share. The 2020 Notes are convertible, at the option of the holder, prior to June 15, 2020, upon the occurrence of specific events, including but not limited to a change in control, or if the closing sales price of the Company's common stock for at least 20 trading days in the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is more than 150% of the applicable conversion price in effect for the notes on the last trading day of the immediately preceding quarter. In the event that all or substantially all of the Company's common stock is acquired on or prior to the maturity of the 2020 Notes in a transaction in which the consideration paid to holders of the Company's common stock consists of all or substantially all cash, the Company would be required to make additional payments in the form of additional shares of common stock to the holders of the 2020 Notes in an aggregate value ranging from $0 to approximately $397 million depending upon the date of the transaction and the then current stock price of the Company. As of March 15, 2020, holders will have the right to convert all or any portion of the 2020 Notes. The 2020 Notes may not be redeemed by the Company prior to maturity. The holders may require the Company to repurchase the 2020 Notes for cash in certain circumstances. Interest on the 2020 Notes is payable on June 15 and December 15 of each year.

In March 2012, the Company issued in a private placement $1.0 billion aggregate principal amount of Convertible Senior Notes due March 15, 2018, with an interest rate of 1.0% (the "2018 Notes"). The Company paid $20.9 million in debt issuance costs during the year ended December 31, 2012, related to this offering. The 2018 Notes are convertible, subject to certain conditions, into the Company's common stock at a conversion price of approximately $944.61 per share. The 2018 Notes are convertible, at the option of the holder, prior to March 15, 2018, upon the occurrence of specific events, including but not limited to a change in control, or if the closing sales price of the Company's common stock for at least 20 trading days in the period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is more than 150% of the applicable conversion price in effect for the notes on the last trading day of the immediately preceding quarter. In the event that all or substantially all of the Company's common stock is acquired on or prior to the maturity of the 2018 Notes in a transaction in which the consideration paid to holders of the Company's common stock consists of all or substantially all cash, the Company would be required to make additional payments in the form of additional shares of common stock to the holders of the 2018 Notes in aggregate value ranging from $0 to approximately $344 million depending upon the date of the transaction and the then current stock price of the Company. As of December 15, 2017, holders will have the right to convert all or any portion of the 2018 Notes. The 2018 Notes may not be redeemed by the Company prior to maturity. The holders may require the Company to repurchase the 2018 Notes for cash in certain circumstances. Interest on the 2018 Notes is payable on March 15 and September 15 of each year.

In March 2010, the Company issued in a private placement $575.0 million aggregate principal amount of Convertible Senior Notes due March 15, 2015, with an interest rate of 1.25% (the "2015 Notes"). The Company paid $13.3 million in debt issuance costs associated with the 2015 Notes for the year ended December 31, 2010. The 2015 Notes are convertible, subject to certain conditions, into the Company's common stock at a conversion price of approximately $303.06 per share. The 2015 Notes are convertible, at the option of the holder, prior to March 15, 2015, upon the occurrence of specified events, including, but not limited to a change in control, or if the closing sales price of the Company's common stock for at least 20 trading days in the period of the 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is more than 150% of the applicable conversion price in effect for the notes on the last trading day of the immediately preceding quarter. The 2015 Notes are currently convertible and will remain convertible until the trading day prior to the maturity date of March 15, 2015, regardless of the Company's stock price. The 2015 Notes may not be redeemed by the Company prior to maturity. The holders may require the Company to repurchase the 2015 Notes for cash in certain circumstances. Interest on the 2015 Notes is payable on March 15 and September 15 of each year.

Accounting guidance requires that cash-settled convertible debt, such as the Company's Convertible Senior Notes, be separated into debt and equity components at issuance and each be assigned a value. The value assigned to the debt component is the estimated fair value, as of the issuance date, of a similar bond without the conversion feature. The difference between the bond cash proceeds and this estimated fair value, representing the value assigned to the equity component, is recorded as a debt discount. Debt discount is amortized using the effective interest method over the period from the origination date through the stated maturity date. The Company estimated the straight debt borrowing rates at debt origination to be 5.89% for the 2015 Notes, 3.50% for the 2018 Notes, 3.13% for the 2020 Notes and 3.18% for the 2021 Notes. The yield to maturity was estimated at an at-market coupon priced at par.

Debt discount after tax of $69.1 million ($115.2 million before tax) net of financing costs associated with the equity component of convertible debt of $1.6 million after tax were recorded in additional paid-in capital related to the 2015 Notes in March 2010. Debt discount after tax of $80.9 million ($135.2 million before tax) net of financing costs associated with the equity component of convertible debt of $2.8 million after tax were recorded in additional paid-in capital related to the 2018 Notes in March 2012. Debt discount after tax of $92.4 million ($154.3 million before tax) and financing costs associated with the equity component of convertible debt of $0.1 million after tax were recorded in additional paid-in capital related to the 2020 Notes at June 30, 2013. Debt discount after tax of $82.5 million ($142.9 million before tax) net of financing costs associated with the equity component of convertible debt of $1.6 million after tax were recorded in additional paid-in capital related to the 2021 Notes at December 31, 2014.

For the years ended December 31, 2014, 2013 and 2012, the Company recognized interest expense of $75.3 million, $78.2 million and $59.4 million, respectively, related to convertible notes, comprised of $17.1 million, $17.7 million and $15.2 million, respectively, for the contractual coupon interest, $54.4 million, $55.7 million and $39.8 million, respectively, related to the amortization of debt discount and $3.8 million, $4.8 million and $4.4 million, respectively, related to the amortization of debt issuance costs. For the years ended December 31, 2014 and 2013, included in the amortization of debt discount mentioned above was $2.6 million and $1.5 million, respectively, of original issuance discount amortization related to the 2020 Notes. In addition, the Company incurred interest expense for the write off of unamortized debt issuance costs related to debt conversions of $0.5 million and $2.4 million for the years ended December 31, 2014 and 2013, respectively. The remaining period for amortization of debt discount and debt issuance costs is the period until the stated maturity date for the respective debt. The weighted-average effective interest rates for the years ended December 31, 2014, 2013, and 2012 are 3.5%, 4.5% and 4.8%, respectively.

In addition, if the Company's convertible debt is redeemed or converted prior to maturity, a gain or loss on extinguishment is recognized. The gain or loss is the difference between the fair value of the debt component immediately prior to extinguishment and its carrying value. To estimate the fair value of the debt at the conversion date, the Company estimated its straight debt borrowing rate, considering its credit rating and straight debt of comparable corporate issuers. For the year ended December 31, 2014 and 2013, the Company recognized non-cash losses of $6.3 million ($3.8 million after tax) and $26.7 million ($16.2 million after tax), respectively, in "Foreign currency transactions and other" in the Consolidated Statements of Operations in connection with the conversion of the 2015 Notes.

Euro Denominated Debt

In September 2014, the Company issued Senior Notes due September 23, 2024, with an interest rate of 2.375% (the "2024 Notes") for an aggregate principal amount of 1.0 billion Euros. The 2024 Notes were issued with an initial discount of 9.4 million Euros. In addition, the Company paid $6.5 million in debt issuance costs during the year ended December 31, 2014. Interest on the 2024 Notes is payable annually on September 23, beginning September 23, 2015. Subject to certain limited exceptions, all payments of interest and principal, including payments made upon any redemption of the 2024 Notes, will be made in Euros.

The aggregate principal value of the 2024 Notes and accrued interest thereon are designated as a hedge of the Company's net investment in a Euro functional currency subsidiary. The foreign currency transaction gains or losses on these liabilities are measured based on changes in spot rates and are recorded in accumulated other comprehensive income (loss). The Euro denominated net assets of the subsidiary are translated into U.S. Dollars at each balance sheet date, with effects of foreign currency changes also reported in accumulated other comprehensive income (loss). Since the notional amount of the recorded Euro denominated debt and related interest are not greater than the notional amount of the Company's net investment, the Company does not expect to incur any ineffectiveness on this hedge.
For the year ended December 31, 2014, the Company recognized interest expense of $8.6 million related to the 2024 Notes. The remaining period for amortization of debt discount and debt issuance costs is the stated maturity date for this debt. The effective interest rate for the year ended December 31, 2014 was 2.5%.

TREASURY_STOCK

TREASURY STOCK	12 Months Ended
TREASURY STOCK	Dec. 31, 2014
Equity [Abstract]
TREASURY STOCK	TREASURY STOCK

	In the second quarter of 2013, the Company's Board of Directors authorized a program to purchase $1.0 billion of the Company's common stock, in addition to amounts previously authorized. In the second quarter of 2013, the Company repurchased 431,910 shares for an aggregate cost of $345.5 million in privately negotiated, off-market transactions and in the third and fourth quarters of 2014, the Company repurchased 114,645 shares of its common stock in privately negotiated, off-market transactions and 438,897 shares of its common stock in the open market for aggregate costs of $147.3 million and $500.0 million, respectively, related to this authorization. The Company has $7.2 million remaining to repurchase common stock related to this authorization.

	In connection with the issuance of the 2018 Notes, the Company repurchased 263,913 shares in the first quarter of 2012 for an aggregate cost of $166.2 million.

	In the third quarter of 2013, the Company repurchased 484,361 shares for an aggregate cost of $459.2 million. These shares were covered under our remaining authorizations as of December 31, 2012 to repurchase common stock.

	In October 2013, the Company settled Conversion Spread Hedges and received 42,160 shares of common stock, with a fair value of $43.1 million, from the counterparties (see Note 7 for further detail on the Conversion Spread Hedges).

	The Board of Directors has also given the Company the general authorization to repurchase shares of its common stock to satisfy employee withholding tax obligations related to stock-based compensation. In the years ended December 31, 2014, 2013 and 2012, the Company repurchased 77,761, 113,503, and 141,229 shares at an aggregate cost of approximately $103.1 million, $78.8 million and $90.8 million, respectively, to satisfy employee withholding taxes related to stock-based compensation.

	The Company may make additional repurchases of shares under its stock repurchase program, depending on prevailing market conditions, alternate uses of capital and other factors. On February 5, 2015, the Company's Board of Directors authorized the Company to repurchase up to an additional $3.0 billion of the Company's common stock. Whether and when to initiate and/or complete any purchase of common stock and the amount of common stock purchased will be determined in the Company's complete discretion. As of December 31, 2014, there were approximately 9.9 million shares of the Company's common stock held in treasury.

REDEEMABLE_NONCONTROLLING_INTE

REDEEMABLE NONCONTROLLING INTERESTS	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
REDEEMABLE NONCONTROLLING INTERESTS	REDEEMABLE NONCONTROLLING INTERESTS

	On May 18, 2010, the Company, through its wholly-owned subsidiary, priceline.com International Ltd. ("PIL"), paid $108.5 million, net of cash acquired, to purchase a controlling interest of the outstanding equity of TravelJigsaw Holdings Limited (now known as rentalcars.com), a Manchester, U.K.-based international rental car reservation service. Certain key members of rentalcars.com's management team retained a noncontrolling ownership interest in rentalcars.com. In addition, certain key members of the management team of Booking.com purchased a 3% ownership interest in rentalcars.com from PIL in June 2010 (together with rentalcars.com management's investment, the "Redeemable Shares"). The holders of the Redeemable Shares had the right to put their shares to PIL and PIL had the right to call the shares in each case at a purchase price reflecting the fair value of the Redeemable Shares at the time of exercise. Subject to certain exceptions, one-third of the Redeemable Shares were subject to the put and call options in each of 2011, 2012 and 2013, respectively, during specified option exercise periods.

	In April 2012 and 2011, in connection with the exercise of call and put options, PIL purchased a portion of the shares underlying redeemable noncontrolling interests for an aggregate purchase price of approximately $61.1 million and $13.0 million, respectively. As a result of the April 2011 purchase, the redeemable noncontrolling interests in rentalcars.com were reduced from 24.4% to 19.0%. As a result of the April 2012 purchase, the redeemable noncontrolling interests in rentalcars.com were further reduced to 12.7%. In April 2013, in connection with the exercise of the March 2013 call and put options, PIL purchased the remaining outstanding shares underlying redeemable noncontrolling interests for an aggregate purchase price of approximately $192.5 million.

	Redeemable noncontrolling interests are measured at fair value, both at the date of acquisition and subsequently at each reporting period. The redeemable noncontrolling interests are reported on the Consolidated Balance Sheets in mezzanine equity in "Redeemable noncontrolling interests."

	A reconciliation of redeemable noncontrolling interests for the years ended December 31, 2013 and 2012 is as follows (in thousands):



		2013			2012
	Balance, beginning of period	$	160,287		$	127,045

	Net income attributable to noncontrolling interests	135			4,471

	Fair value adjustments(1)	42,522			84,693

	Purchase of subsidiary shares at fair value(1)	(192,530		)	(61,079		)
	Currency translation adjustments	(10,414		)	5,157

	Balance, end of period	$	—		$	160,287

	_____________________________
	(1) The fair value of the redeemable noncontrolling interests was determined by industry peer comparable analysis and a discounted cash flow valuation model.

ACCUMULATED_OTHER_COMPREHENSIV

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	12 Months Ended
	Dec. 31, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)

	The table below provides the balances for each classification of accumulated other comprehensive income (loss) as of December 31, 2014 and 2013 (in thousands):



		December 31, 2014			December 31, 2013
	Foreign currency translation adjustments, net of tax (1)	$	(102,758	)	$	84,598

	Net unrealized gain (loss) on investment securities, net of tax (2)	(157,144		)	131

	Accumulated other comprehensive income (loss)	$	(259,902	)	$	84,729

	_____________________________
	(1) Foreign currency translation adjustments, net of tax, includes net losses from fair value adjustments at December 31, 2014 of $37.8 million after tax ($57.8 million before tax) and a net losses from fair value adjustments at December 31, 2013 of $58.7 million after tax ($98.8 million before tax) associated with derivatives designated as net investment hedges (see Note 5).

	Foreign currency translation adjustments, net of tax, includes foreign currency transaction gains at December 31, 2014 of $48.3 million after tax ($83.8 million before tax) associated with the Company's 2024 Notes, which are Euro denominated debt, designated as a net investment hedge (see Note 11).

	The remaining balance in currency translation adjustments excludes income taxes as a result of the Company's intention to indefinitely reinvest the earnings of its non-U.S. subsidiaries outside of the United States.

	(2) The unrealized loss before tax at December 31, 2014 was $164.7 million compared to an unrealized gain before tax at December 31, 2013 of $0.2 million.

INCOME_TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES

	International pre-tax income was $2.9 billion, $2.2 billion and $1.7 billion for the years ended December 31, 2014, 2013 and 2012, respectively. Domestic pre-tax income was $98.4 million, $48.5 million, and $95.0 million for the years ended December 31, 2014, 2013, and 2012, respectively.

	The income tax expense (benefit) for the year ended December 31, 2014 is as follows (in thousands):



		Current			Deferred				Total
	International	$	496,719		$	(10,613	)		$	486,106

	U.S. Federal	10,316			47,847				58,163

	U.S. State	28,953			(5,527		)		23,426

	Total	$	535,988		$	31,707			$	567,695


	The income tax expense (benefit) for the year ended December 31, 2013 is as follows (in thousands):



		Current			Deferred				Total
	International	$	396,162		$	(16,314	)		$	379,848

	U.S. Federal	5,250			11,454				16,704

	U.S. State	13,431			(6,244		)		7,187

	Total	$	414,843		$	(11,104	)		$	403,739


	The income tax expense (benefit) for the year ended December 31, 2012 is as follows (in thousands):



		Current			Deferred				Total
	International	$	302,352		$	(13,792	)		$	288,560

	U.S. Federal	3,681			37,956				41,637

	U.S. State	12,203			(4,568		)		7,635

	Total	$	318,236		$	19,596			$	337,832


	The Company has significant deferred tax assets, resulting principally from U.S. net operating loss carryforwards ("NOLs"). The amount of NOLs available for the Company's use is limited by Section 382 of the Internal Revenue Code ("IRC Section 382"). IRC Section 382 imposes limitations on the availability of a company's NOLs after a more than 50% ownership change occurs. It was determined that ownership changes, as defined in IRC Section 382 have occurred. The amount of the Company's NOLs incurred prior to each ownership change is limited based on the value of the Company on the respective dates of ownership change.

	At December 31, 2014, after considering the impact of IRC Section 382, the Company had approximately $1.2 billion of available NOL's for U.S. federal income tax purposes, comprised of approximately $22 million of NOLs generated from operating losses and approximately $1.2 billion of NOLs generated from equity-related transactions, including equity-based compensation and stock warrants. The NOLs mainly expire from December 31, 2019 to December 31, 2021. The utilization of these NOLs is dependent upon the Company's ability to generate sufficient future taxable income in the United States. The Company periodically evaluates the likelihood of the realization of deferred tax assets, and reduces the carrying amount of these deferred tax assets by a valuation allowance to the extent it believes a portion will not be realized. The Company considers many factors when assessing the likelihood of future realization of the deferred tax assets, including its recent cumulative earnings experience by taxing jurisdiction, expectations of future income, the carryforward periods available for tax reporting purposes, and other relevant factors.

	The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities at December 31, 2014 and 2013 are as follows (in thousands):



		2014			2013
	Deferred tax assets/(liabilities):

	Net operating loss carryforward — U.S.	$	176,786		$	263,994

	Net operating loss carryforward — International	22,353			21,660

	Fixed assets	—			818

	Accrued expenses	41,117			22,708

Stock-based compensation and other stock based payments	54,935			40,346

Other	24,456			33,530

Subtotal	319,647			383,056


Discount on convertible notes	(141,193		)	(97,550		)
Intangible assets and other	(856,807		)	(356,669		)
Euro denominated debt	(35,441		)	—

Fixed assets	(3,409		)	—

Less valuation allowance on deferred tax assets	(161,997		)	(173,558		)
Net deferred tax assets (liabilities)(1)	$	(879,200	)	$	(244,721	)

(1) Includes non-current deferred tax assets of $8.5 million and $7.1 million as of December 31, 2014 and 2013, respectively, reported in "Other assets" on the Consolidated Balance Sheets and current deferred tax liabilities of $1.2 million and $38 thousand as of December 31, 2014 and 2013, respectively, reported in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheets.

The valuation allowance on deferred tax assets of $162.0 million at December 31, 2014 includes $140.4 million related to U.S. federal net operating loss carryforwards derived from equity transactions and $21.6 million related to international operations. Additionally, since January 1, 2006, the Company has generated additional federal tax benefits of $250.0 million related to equity transactions that are not included in the deferred tax asset table above. Pursuant to accounting guidance, these tax benefits related to equity deductions will be recognized by crediting paid in capital, if and when they are realized by reducing the Company's current income tax liability.

It is the practice and intention of the Company to reinvest the earnings of its non-U.S. subsidiaries in those operations. Thus at December 31, 2014, no provision had been made for U.S. taxes on approximately $7.3 billion of international earnings because such earnings are intended to be indefinitely reinvested outside of the United States. It is not practicable to determine the U.S. federal income tax liability that would be payable if such earnings were not indefinitely reinvested.

At December 31, 2014, the Company has approximately $673.4 million of U.S. state net operating loss carryforwards that expire mainly between December 31, 2020 and December 31, 2033, $131.2 million of non-U.S. net operating loss carryforwards, of which $49.3 million expire between December 31, 2019 and December 31, 2021 and $3.7 million which expire between December 31, 2028 and December 31, 2030, and $1.7 million of foreign capital allowance carryforwards that do not expire. At December 31, 2014, the Company also had approximately $29.6 million of U.S. research credit carryforwards that mainly expire between December 31, 2033 and December 31, 2034 and are also subject to annual limitation.

A significant portion of the Company's taxable earnings are derived from the Netherlands. Under Dutch corporate income tax law, income generated from qualifying innovative activities is taxed at a rate of 5% ("Innovation Box Tax") rather than the Dutch statutory rate of 25%. Booking.com obtained a ruling from the Dutch tax authorities in February 2011 confirming that a portion of its earnings ("qualifying earnings") is eligible for Innovation Box Tax treatment. The ruling from the Dutch tax authorities is valid until December 31, 2017.

The effective income tax rate of the Company is different from the amount computed using the expected U.S. statutory federal rate of 35% as a result of the following items (in thousands):



	2014			2013				2012
Income tax expense at federal statutory rate	$	1,046,307		$	803,788			$	616,654

Adjustment due to:

Foreign rate differential	(289,692		)	(226,894		)		(175,932		)
Innovation Box Tax benefit	(233,545		)	(177,195		)		(118,916		)
Other	44,625			4,040				16,026

Income tax expense	$	567,695		$	403,739			$	337,832


The Company accounts for uncertain tax positions based on a two step approach of recognition and measurement. The first step involves assessing whether the tax position is more likely than not to be sustained upon examination based upon its technical merits. The second step involves measurement of the amount to recognize. Tax positions that meet the more likely than not threshold are measured at the largest amount of tax benefit that is greater than 50% likely of being realized upon ultimate finalization with the taxing authority.

The following is a reconciliation of the total amount of unrecognized tax benefits (in thousands):



	2014			2013				2012
Unrecognized tax benefit — January 1	$	22,104		$	7,343			$	3,192

Gross increases — tax positions in current period	9,305			8,597				4,423

Gross increases — tax positions in prior periods	6,569			3,507				343

Increase acquired in business combination	17,767			7,089				—

Gross decreases — tax positions in prior periods	(2,164		)	(495		)		(615		)
Reduction due to lapse in statute of limitations	(346		)	(3,937		)		—

Reduction due to settlements during the current period	(879		)	—				—

Unrecognized tax benefit — December 31	$	52,356		$	22,104			$	7,343


The unrecognized tax benefits are included in "Other long-term liabilities" on the Consolidated Balance Sheets for the years ended December 31, 2014 and 2013. The Company does not expect further significant changes in the amount of unrecognized tax benefits during the next twelve months.

The Company's Netherlands, U.S. federal and Connecticut, Singapore, and U.K. income tax returns, constituting the returns of the major taxing jurisdictions, are subject to examination by the taxing authorities as prescribed by applicable statute. The statute of limitations remains open for: the Company's Netherlands returns from 2008 and forward; the Company's Singapore returns from 2011 and forward; the Company's U.S. Federal and Connecticut returns from 2011 and forward; and the Company's U.K. returns for the tax years 2008, 2013, and 2014. No income tax waivers have been executed that would extend the period subject to examination beyond the period prescribed by statute in the major taxing jurisdictions in which the company is a taxpayer.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

Competition Reviews

In July 2012, the Office of Fair Trading (the "OFT"), the predecessor competition authority in the United Kingdom to the Competition and Markets Authority ("CMA"), issued a "Statement of Objections" ("SO") to Booking.com, which set out the OFT's preliminary views on why it believed Booking.com and others in the online hotel reservation industry were allegedly in breach of E.U. and U.K. competition law. The SO alleged, among other things, that there were agreements or concerted practices between hotels and Booking.com and between hotels and at least one other OTC that restricted Booking.com's (and the other OTC's) ability to discount hotel room reservations, which the OFT alleged was a form of resale price maintenance. The Company disputes the allegations in the SO.

On January 31, 2014, the OFT announced that it had accepted commitments offered by Booking.com, as well as Expedia and Intercontinental Hotel Group, (the "Commitments") to close the investigation on the basis that they address the OFT's competition concerns. The OFT closed its investigation with no finding of infringement or admission of wrongdoing and no imposition of a fine.

The Commitments provide, among other things, that hotels will continue to be able to set retail prices for hotel room reservations on all OTC websites, such as Booking.com. Under the Commitments, OTCs, such as Booking.com, have the flexibility to discount a hotel's retail price, but only to members of closed groups, a concept that is defined in the Commitments, who have previously made a reservation through the OTC. The discount may be up to Booking.com's commission. In addition, the Commitments provide that Booking.com will not require rate parity from hotels in relation to discounted rates that are provided by other OTCs or hotels to members of their closed groups, provided the discounted rate is not made public. The Commitments apply to bookings by European Economic Area residents at U.K. hotels.

On March 31, 2014, Skyscanner, a meta-search site based in the United Kingdom, filed an appeal in the Competition Appeal Tribunal ("CAT") against the OFT's decision to accept the Commitments. Booking.com intervened in support of the CMA in the CAT. In its decision dated September 26, 2014, the CAT found that the CMA was wrong to reject Skyscanner's arguments about the negative impact of the Commitments on its business and price transparency generally without properly exploring these arguments. The CAT's decision vacates the CMA's Commitments decision and remits the matter to the CMA for reconsideration in accordance with the CAT's ruling. The CMA did not appeal the CAT's decision. It is uncertain what action the CMA will take in response to the CAT's ruling, which could involve re-opening, closing or suspending the investigation.

Investigations have also been opened by the national competition authorities in the Czech Republic, France, Germany, Italy, Austria, Hungary, Sweden, Ireland, Denmark and Switzerland that focus on Booking.com's rate parity clause in its contracts with accommodation providers in those jurisdictions. Competition related inquiries have also been received from the competition authority in China. The Company is in ongoing discussions with the relevant regulatory authorities regarding their concerns. The Company is currently unable to predict the outcome of these investigations or how the Company's business may be affected. Possible outcomes include requiring Booking.com to amend or remove its rate parity clause from its contracts with accommodation providers in those jurisdictions and/or the imposition of fines.

On December 15, 2014, the French, Italian and Swedish national competition authorities, working in close cooperation with the European Commission, announced their intention to seek public feedback on commitments offered by Booking.com in connection with investigations of Booking.com's rate parity provisions in its contractual arrangements with accommodation providers. If the proposed commitments are accepted by the French, Italian and Swedish competition authorities, the investigations in those countries will be closed with no finding of infringement or admission of wrongdoing and no imposition of a fine. Under the terms of the proposed commitments, Booking.com would replace its existing price parity agreements with accommodation providers - sometimes also referred to as "most favored nation" or "MFN" provisions - with "narrow" price parity agreements. Under the "narrow" price parity agreement, an accommodation provider would still be required to offer the same or better rates on Booking.com as it offered to a consumer directly, but it would no longer be required to offer the same or better rates on Booking.com as it offered to other on-line travel companies. If the commitments are accepted by the French, Italian and Swedish competition authorities after they have been market tested, Booking.com will implement the commitments within six months of their being accepted. The Company is currently unable to predict the outcome of the market test of the proposed commitments offered in France, Italy and Sweden or the impact the proposed commitments in France, Italy and Sweden will have on the on-going investigations in other European countries or how its business may be affected by the proposed commitments if accepted. The Company notes that the German competition authority has required Hotel Reservation Service to remove its rate parity clause from its contracts with hotels, and Hotel Reservation Service's initial appeal was denied. To the extent that regulatory authorities require changes to the Company's business practices or to those currently common to the industry, the Company's business, competitive position and results of operations could be materially and adversely affected. Negative publicity regarding any such investigations could adversely affect the Company's brands and therefore its market share and results of operations.

Lawsuits Alleging Antitrust Violations

On August 20, 2012, one complaint was filed on behalf of a putative class of persons who purchased hotel room reservations from certain hotels (the "Hotel Defendants") through certain OTC defendants, including the Company. The initial complaint, Turik v. Expedia, Inc., Case No. 12-cv-4365, filed in the U.S. District Court for the Northern District of California, alleged that the Hotel Defendants and the OTC defendants violated U.S. federal and state laws by entering into a conspiracy to enforce a minimum resale price maintenance scheme pursuant to which putative class members paid inflated prices for hotel room reservations that they purchased through the OTC defendants. Thirty-one other complaints containing similar allegations were filed in a number of federal jurisdictions across the country. Plaintiffs in these actions sought treble damages and injunctive relief.

The Judicial Panel on Multidistrict Litigation ("JPML") consolidated all of the pending cases under 28 U.S.C. §1407 before Judge Boyle in the U.S. District Court for the Northern District of Texas. On May 1, 2013, an amended consolidated complaint was filed.

On February 18, 2014, Judge Boyle dismissed the amended consolidated complaint without prejudice. On October 27, 2014 the court denied plaintiffs' motion for leave to file a proposed Second Consolidated Amended Complaint, and on October 28, 2014 the court issued a final judgment dismissing the case with prejudice. The time to appeal the court's October 27, 2014 decision has expired and the matter is closed.

Litigation Related to Travel Transaction Taxes

The Company and certain third-party online travel companies ("OTCs") are currently involved in approximately forty lawsuits, including certified and putative class actions, brought by or against U.S. states, cities and counties over issues involving the payment of travel transaction taxes (e.g., hotel occupancy taxes, excise taxes, sales taxes, etc.). The Company's subsidiaries priceline.com LLC, Lowestfare.com LLC and Travelweb LLC are named in some but not all of these cases. Generally, the complaints allege, among other things, that the OTCs violated each jurisdiction's respective relevant travel transaction tax ordinance with respect to the charge and remittance of amounts to cover taxes under each law. The complaints typically seek compensatory damages, disgorgement, penalties available by law, attorneys' fees and other relief. In addition, approximately seventy-nine municipalities or counties, and at least eleven states, have initiated audit proceedings (including proceedings initiated by more than forty municipalities in California, which have been inactive for several years), issued proposed tax assessments or started inquiries relating to the payment of travel transaction taxes. Additional state and local jurisdictions are likely to assert that the Company is subject to travel transaction taxes and could seek to collect such taxes, retroactively and/or prospectively.

With respect to the principal claims in these matters, the Company believes that the laws at issue do not apply to the services it provides, namely the facilitation of travel reservations, and, therefore, that it does not owe the taxes that are claimed to be owed. Rather, the Company believes that the laws at issue generally impose travel transaction taxes on entities that own, operate or control hotels (or similar businesses) or furnish or provide hotel rooms or similar accommodations or other travel services. In addition, in many of these matters, the taxing jurisdictions have asserted claims for "conversion" - essentially, that the Company has collected a tax and wrongfully "pocketed" those tax dollars - a claim that the Company believes is without basis and has vigorously contested. The taxing jurisdictions that are currently involved in litigation and other proceedings with the Company, and that may be involved in future proceedings, have asserted contrary positions and will likely continue to do so. From time to time, the Company has found it expedient to settle, and may in the future agree to settle, claims pending in these matters without conceding that the claims at issue are meritorious or that the claimed taxes are in fact due to be paid.

In connection with some of these tax audits and assessments, the Company may be required to pay any assessed taxes, which amounts may be substantial, prior to being allowed to contest the assessments and the applicability of the laws in judicial proceedings. This requirement is commonly referred to as "pay to play" or "pay first." For example, the City and County of San Francisco assessed the Company approximately $3.4 million (an amount that includes interest and penalties) relating to hotel occupancy taxes, which the Company paid in July 2009, and issued a second assessment totaling approximately $2.7 million, which the Company paid in January 2013. Payment of these amounts, if any, is not an admission that the Company believes it is subject to such taxes. In the San Francisco action, for example, the court ruled in February 2013 that the Company and OTCs do not owe transient accommodations tax to the city and ordered the city to refund the amount paid in July 2009; the Company also is seeking a refund of the amount paid in January 2013. San Francisco has appealed the court's ruling and has not refunded the amount paid in July 2009 pending resolution of the appeal. The matter has been stayed while the appeal in another case with the City of San Diego is pending before the California Supreme Court.

Litigation is subject to uncertainty and there could be adverse developments in these pending or future cases and proceedings. For example, in January 2013, the Tax Appeal Court for the State of Hawaii held that the Company and other OTCs are not liable for the State's transient accommodations tax, but held that the OTCs, including the Company, are liable for the State's general excise tax on the full amount the OTC collects from the customer for a hotel room reservation, without any offset for amounts passed through to the hotel. The Company recorded an accrual for travel transaction taxes (including estimated interest and penalties), with a corresponding charge to cost of revenues, of approximately $16.5 million in December 2012 and approximately $18.7 million in the three months ended March 31, 2013, primarily related to this ruling. During the years ended December 31, 2013 and December 31, 2014, the Company paid approximately $20.6 million and $2.2 million, respectively, to the State of Hawaii related to this ruling. The Company has filed an appeal now pending before the Hawaii Supreme Court.

Other adverse rulings include a decision in September 2012, in which the Superior Court in the District of Columbia granted summary judgment in favor of the District and against the OTCs ruling that tax is due on the OTCs' margin and service fees, which the Company is appealing. As a result, the Company increased its accrual for travel transaction taxes (including estimated interest), with a corresponding charge to cost of revenues, by approximately $4.8 million in September 2012 and by approximately $5.6 million in the three months ended March 31, 2013. Also, in July 2013, the Circuit Court of Cook County, Illinois, ruled that the Company and the other OTCs are liable for tax and other obligations under the Chicago Hotel Accommodations Tax. In July 2014, the Company resolved all claims in this case through settlement and the claims against the Company were dismissed on September 3, 2014. In addition, in October 2009, a jury in a San Antonio class action found that the Company and the other OTCs that are defendants in the lawsuit "control" hotels for purposes of the local hotel occupancy tax ordinances at issue and are, therefore, subject to the requirements of those ordinances. The Company intends to vigorously appeal the trial court's judgment when it becomes final.

An unfavorable outcome or settlement of pending litigation may encourage the commencement of additional litigation, audit proceedings or other regulatory inquiries and also could result in substantial liabilities for past and/or future bookings, including, among other things, interest, penalties, punitive damages and/or attorney fees and costs. There have been, and will continue to be, substantial ongoing costs, which may include "pay first" payments, associated with defending the Company's position in pending and any future cases or proceedings. An adverse outcome in one or more of these unresolved proceedings could have a material adverse effect on the Company's business and could be material to the Company's results of operations or cash flow in any given operating period. However, the Company believes that even if it were to suffer adverse determinations in the near term in more of the pending proceedings than currently anticipated, given results to date it would not have a material impact on the Company's liquidity because of the Company's available cash.

To the extent that any tax authority succeeds in asserting that the Company's services are subject to travel transaction taxes and that the Company has a tax collection responsibility for those taxes, or the Company determines that it has such a responsibility, with respect to future transactions the Company may collect any such additional tax obligation from its customers, which would have the effect of increasing the cost of travel reservations to its customers and, consequently, could make the Company's travel reservation services less competitive (as compared to the services of other OTCs or travel service providers) and reduce the Company's travel reservation transactions; alternatively, the Company could choose to reduce the compensation for its services. Either action could have a material adverse effect on the Company's business and results of operations.

In many of the judicial and other proceedings initiated to date, the taxing jurisdictions seek not only historical taxes that are claimed to be owed on the Company's gross profit, but also, among other things, interest, penalties, punitive damages and/or attorney fees and costs. Therefore, any liability associated with travel transaction tax matters is not constrained to the Company's liability for tax owed on its historical gross profit, but may also include, among other things, penalties, interest and attorneys' fees. To date, the majority of the taxing jurisdictions in which the Company facilitates hotel reservations have not asserted that these taxes are due and payable. With respect to taxing jurisdictions that have not initiated proceedings to date, it is possible that they will do so in the future or that they will seek to amend their tax statutes and seek to collect taxes from the Company only on a prospective basis.

Accrual for Travel Transaction Taxes

As a result of this litigation and other attempts by jurisdictions to levy similar taxes, the Company has established an accrual (including estimated interest and penalties) for the potential resolution of issues related to travel transaction taxes in the amount of approximately $52 million at December 31, 2014 compared to approximately $55 million at December 31, 2013. The Company's legal expenses for these matters are expensed as incurred and are not reflected in the amount accrued. The actual cost may be less or greater, potentially significantly, than the liabilities recorded. An estimate for a reasonably possible loss or range of loss in excess of the amount accrued cannot be reasonably made.

The Company intends to vigorously defend against the claims in all of the proceedings described below.

Statewide Class Actions and Putative Class Actions

Such actions include:

•

City of Los Angeles, California v. Hotels.com, Inc., et al. (California Superior Court, Los Angeles County; filed in December 2004); (California Court of Appeal; appeal filed in March 2014);

•

City of San Antonio, Texas v. Hotels.com, L.P., et al. (U.S. District Court for the Western District of Texas; filed in May 2006);

•

Pine Bluff Advertising and Promotion Commission, Jefferson County, Arkansas, et al. v. Hotels.com, LP, et al. (Circuit Court of Jefferson County, Arkansas; filed in September 2009); (Arkansas Supreme Court; appeal filed in March 2013);

•

County of Lawrence, Pennsylvania v. Hotels.com, L.P., et al. (Court of Common Pleas of Lawrence County, Pennsylvania; filed Nov. 2009); (Commonwealth Court of Pennsylvania; appeal filed in November 2010);

•

City of Columbia, South Carolina, et al. v. Hotelguides.com, Inc. et al. (Court of Common Pleas, Ninth Judicial Circuit, County of Charleston; filed in July 2013); and

•

City of Charleston, et al. v. Hotelguides.com, Inc. et al. (Court of Common Pleas for Charleston County, South Carolina; filed January 2014).

Actions Filed on Behalf of Individual Cities, Counties and States

Such actions include:

•

City of San Diego, California v. Hotels.com L.P., et al. (California Superior Court, San Diego County; filed in September 2006) (Superior Court of California, Los Angeles County) (California Court of Appeal; appeal filed in August 2012); (California Supreme Court; petition for review granted in July 2014);

•

City of Atlanta, Georgia v. Hotels.com L.P., et al. (Superior Court of Fulton County, Georgia; filed in March 2006); (Court of Appeals of the State of Georgia; appeal filed in January 2007); (Georgia Supreme Court; further appeal filed in December 2007; petition for writs of mandamus and prohibition filed in December 2012; further appeal filed in November 2013 but transferred to Georgia Court of Appeals in July 2014);

•

Leon County, et al. v. Expedia, Inc., et al. (Second Judicial Circuit Court for Leon County, Florida; filed November 2009); (Florida First District Court of Appeal; appeal filed in May 2012); (Florida Supreme Court; jurisdiction accepted in September 2013);

•

Leon County v. Expedia, Inc. et al. (Second Judicial Circuit Court for Leon County, Florida; filed in December 2009); (Florida First District Court of Appeal; appeal filed in October 2012); (Florida Supreme Court; notice to invoke jurisdiction filed in October 2013);

•

Montana Department of Revenue v. Priceline.com, Inc., et al. (First Judicial District Court of Lewis and Clark County, Montana; filed in November 2010); (Montana Supreme Court; appeal filed in May 2014);

•

District of Columbia v. Expedia, Inc., et al. (Superior Court of District of Columbia; filed in March 2011); (District of Columbia Court of Appeals; appeal filed in March 2014);

•

Volusia County, et al. v. Expedia, Inc., et al. (Circuit Court for Volusia County, Florida; filed in April 2011);

•

Town of Breckenridge, Colorado v. Colorado Travel Company, LLC, et al. (District Court for Summit County, Colorado; filed in July 2011);

•

County of Nassau v. Expedia, Inc., et al. (Supreme Court of Nassau County, New York; filed in September 2011); (Appellate Division, Second Department; appeal filed in April 2013);

•

State of Mississippi v. Priceline.com Inc., et al., (Chancery Court of Hinds County, Mississippi; filed in January 2012);

•

Fargo v. Expedia, Inc. et al. (District Court for the County of Cass; filed in February 2013)

•

Village of Bedford Park, et al. v. Expedia, Inc. et al. (U.S. District Court for the Northern District of Illinois; filed in July 2013);

•

Department of Revenue, Finance and Administration Cabinet, Commonwealth of Kentucky v. Expedia Inc., et al. (Franklin Circuit Court, Kentucky; filed in July 2013);

•

State of New Hampshire v. priceline.com Inc., et al. (Merrimack Superior Court; filed in October 2013);

•

Puerto Rico Tourism Company v. Priceline.com Incorporated, et al. (U.S. District Court for the District of Puerto Rico; filed in April 2014); and

•

City of Phoenix, et al. v. Priceline.com Inc., et al. (Arizona Tax Court; filed in August 2014).

Judicial Actions Relating to Assessments Issued by Individual Cities, Counties and States

The Company may seek judicial review of assessments issued by an individual city or county. Currently pending actions seeking such a review include:

•

Priceline.com, Inc., et al. v. Broward County, Florida (Second Judicial Circuit, Leon County, Florida; filed in January 2009); (Florida First District Court of Appeal; filed in February 2013); (Florida Supreme Court; notice to invoke jurisdiction filed in February 2014);

•

Priceline.com, Inc. v. Indiana Department of State Revenue (Indiana Tax Court; filed in March 2009);

•

Priceline.com, Inc., et al. v. City and County of San Francisco, California, et al. (California Superior Court, County of Los Angeles; filed in June 2009); (California Court of Appeal; appeal filed in December 2013); Priceline.com, Inc. v. City and County of San Francisco, California, et al. (California Superior Court, County of Los Angeles; filed in November 2013);

•

Priceline.com, Inc. v. Miami-Dade County, Florida, et al. (Eleventh Judicial Circuit Court for Miami-Dade, County, Florida; filed in December 2009);

•

priceline.com Incorporated, et al. v. Osceola County, Florida, et al. (Second Judicial Circuit, Leon County, Florida; filed in January 2011);

•

In the Matter of the Tax Appeal of priceline.com Inc. and In the Matter of the Tax Appeal of Travelweb LLC (Tax Appeal Court of the State of Hawaii; filed in March 2011) (Hawaii Supreme Court; appeal transferred in December 2013); In the Matter of the Tax Appeal of priceline.com Inc. and In the Matter of the Tax Appeal of Travelweb LLC (Tax Appeal Court of the State of Hawaii, filed in July 2012) (Hawaii Supreme Court; appeal transferred in December 2013); In the Matter of the Tax Appeal of priceline.com Inc. and In the Matter of Tax Appeal of Travelweb LLC (Tax Appeal Court of the State of Hawaii, filed in June 2013); In the Matter of the Tax Appeal of priceline.com Inc. and In the Matter of Tax Appeal of Travelweb LLC (Tax Appeal Court of the State of Hawaii; filed in January 2014); In the Matter of the Appeal of priceline.com Incorporated (Tax Appeal Court of the State of Hawaii; filed in August 2014);

•

Expedia, Inc. et al. v. City of Portland (Circuit Court for Multnomah County, Oregon, filed in February 2012);

•

Expedia, Inc., et al. v. City and County of Denver, et al. (District Court for Denver County, Colorado, filed in March 2012); (Colorado Court of Appeal; appeal filed in April 2013); (Colorado Supreme Court; petition for review filed in August 2014); and

•

Expedia, Inc., et al. v. Oregon Department of Revenue (Oregon Tax Court; filed in September 2013).

Administrative Proceedings and Other Possible Actions

At various times, the Company has also received inquiries or proposed tax assessments from municipalities and other taxing jurisdictions relating to the Company's charges and remittance of amounts to cover state and local travel transaction taxes. Among others, the City of Paradise Valley, Arizona; fifteen cities (and one county) in Colorado; Arlington, Texas; Lake County, Indiana; and state tax officials from Arkansas, Colorado, Louisiana, Maine, Maryland, Michigan, Minnesota, South Carolina, South Dakota, Texas, Vermont, West Virginia and Wisconsin have begun formal or informal administrative procedures or stated that they may assert claims against the Company relating to allegedly unpaid state or local travel transaction taxes. Between 2008 and 2010, the Company received audit notices from more than forty cities in the state of California. The audit proceedings in those cities have not been active but have not been formally closed. The Company has also been contacted for audit by five counties in the state of Utah.

Patent Infringement

On February 9, 2015, International Business Machines Corporation ("IBM") filed a complaint in the U.S. District Court for the District of Delaware against The Priceline Group Inc. and its subsidiaries KAYAK Software Corporation, OpenTable, Inc. and priceline.com LLC (the "Subject Companies"). In the complaint, IBM alleges that the Subject Companies have infringed and continue to willfully infringe certain IBM patents that IBM claims relate to the presentation of applications and advertising in an interactive service, preserving state information in online transactions and single sign-on processes in a computing environment and seeks unspecified damages (including a request that the amount of compensatory damages be trebled), injunctive relief and costs and reasonable attorneys’ fees. The Company believes the claims to be without merit and intends to contest them vigorously.

Other

The Company intends to defend vigorously against the claims in all of the proceedings described in this Note 16. The Company has accrued for certain legal contingencies where it is probable that a loss has been incurred and the amount can be reasonably estimated. Except as disclosed, such amounts accrued are not material to the Company's consolidated balance sheets and provisions recorded have not been material to the Company's consolidated results of operations or cash flows. The Company is unable to estimate a reasonably possible range of loss.

From time to time, the Company has been, and expects to continue to be, subject to legal proceedings and claims in the ordinary course of business, including claims of alleged infringement of third party intellectual property rights. Such claims, even if not meritorious, could result in the expenditure of significant financial and managerial resources, divert management's attention from the Company's business objectives and adversely affect the Company's business, results of operations, financial condition and cash flows.

Contingent Consideration for Business Acquisitions (see Note 20)

Employment Contracts

The Company has employment agreements with certain members of senior management that provide for cash severance payments of up to approximately $26 million, accelerated vesting of equity instruments, including without limitation, restricted stock, restricted stock units and performance share units upon, among other things, death or termination without "cause" or "good reason," as those terms are defined in the agreements, and a gross-up for the payment of "golden parachute" excise taxes. In addition, certain of the agreements provide for the extension of health and insurance benefits after termination for periods up to three years.

Operating Leases

The Company leases certain facilities and equipment through operating leases. Rental expense for leased office space was approximately $57.2 million, $40.0 million and $30.9 million for the years ended December 31, 2014, 2013 and 2012, respectively. Rental expense for leased facility space was approximately $15 million, $13 million and $11 million for the years ended December 31, 2014, 2013 and 2012, respectively.

The Company's headquarters and the headquarters of the priceline.com business are located in Norwalk, Connecticut, United States of America, where the Company leases approximately 70,000 square feet of office space. The Booking.com business is headquartered in Amsterdam, Netherlands, where the Company leases approximately 202,000 square feet of office space; the KAYAK business is headquartered in Stamford, Connecticut, United States of America, where the Company leases approximately 18,000 square feet of office space; the agoda.com business has significant support operations in Bangkok, Thailand, where the Company leases approximately 118,000 square feet of office space; the OpenTable business is headquartered in San Francisco, California, United States of America, where the Company leases approximately 51,000 square feet of office space; and the rentalcars.com business is headquartered in Manchester, England, where the Company leases approximately 63,000 square feet of office space. The Company leases additional office space to support its operations in various locations around the world, including hosting and data center facilities in the United States, the United Kingdom, Switzerland, the Netherlands and Hong Kong and sales and support facilities in numerous locations.

The Company does not own any real estate as of December 31, 2014. Minimum payments for operating leases for office space, data centers and equipment having initial or remaining non-cancellable terms in excess of one year have been translated into U.S. Dollars at the December 31, 2014 spot exchange rates, as applicable, and are as follows (in thousands):

2015

2016

2017

2018

2019

After

Total

2019

$79,902

$73,853

$59,583

$50,239

$42,918

$130,891

$437,386

BENEFIT_PLANS

BENEFIT PLANS	12 Months Ended
BENEFIT PLANS	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
BENEFIT PLANS	BENEFIT PLANS

	The Company maintains a defined contribution 401(k) savings plan (the "Plan") covering certain U.S. employees. In connection with acquisitions, effective as of the date of such acquisitions, the Company assumed defined contribution plans covering the U.S. employees of the acquired companies. The Company also maintains certain other defined contribution plans outside of the United States for which it provides contributions for participating employees. The Company's matching contributions during the years ended December 31, 2014, 2013 and 2012 were approximately $6.2 million, $5.8 million and $5.0 million, respectively.

GEOGRAPHIC_INFORMATION

GEOGRAPHIC INFORMATION	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
GEOGRAPHIC INFORMATION	GEOGRAPHIC INFORMATION

	The Company's international information consists of the results of Booking.com, agoda.com and rentalcars.com and the results of the internationally based websites of KAYAK since May 21, 2013 and OpenTable since July 24, 2014 (in each case regardless of where the consumer resides, where the consumer is physically located while making a reservation or the location of the travel service provider or restaurant). The Company's geographic information is as follows (in thousands):



		United		The		Other		Total
		States		Netherlands				Company
	2014

	Revenues	$	1,798,484	$	5,519,207	$	1,124,280	$	8,441,971

	Intangible assets, net	2,183,957		108,650		42,154		2,334,761

	Goodwill	2,712,479		224,731		389,264		3,326,474

	Other long-lived assets	80,668		97,056		77,915		255,639


	2013

	Revenues	$	1,769,696	$	4,103,393	$	920,217	$	6,793,306

	Intangible assets, net	838,494		123,847		57,644		1,019,985

	Goodwill	1,247,686		156,261		363,965		1,767,912

	Other long-lived assets	49,750		61,164		64,708		175,622


	2012

	Revenues	$	1,661,710	$	2,675,976	$	923,270	$	5,260,956

	Intangible assets, net	1,337		137,255		69,521		208,113

	Goodwill	37,306		149,464		335,902		522,672

	Other long-lived assets	76,623		37,035		42,924		156,582

SELECTED_QUARTERLY_FINANCIAL_D

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)



		First		Second		Third		Fourth
		Quarter		Quarter		Quarter		Quarter
		(In thousands, except per share data)

	2014


	Total revenues(1)	$	1,641,802	$	2,123,575	$	2,836,497	$	1,840,097


	Gross profit	1,406,471		1,882,996		2,619,978		1,674,685


	Net income	331,218		576,451		1,062,253		451,831


	Net income applicable to common stockholders	331,218		576,451		1,062,253		451,831


	Net income applicable to common stockholders per basic common share	$	6.35	$	11	$	20.27	$	8.65


	Net income applicable to common stockholders per diluted common share	$	6.25	$	10.89	$	20.03	$	8.56





		First		Second		Third		Fourth
		Quarter		Quarter		Quarter		Quarter
		(In thousands, except per share data)

	2013


	Total revenues(1)	$	1,302,012	$	1,680,238	$	2,269,903	$	1,541,153


	Gross profit	1,009,665		1,383,855		1,989,065		1,333,301


	Net income	244,292		437,440		832,989		378,077


	Net income applicable to common stockholders	244,271		437,326		832,989		378,077


	Net income applicable to common stockholders per basic common share	$	4.89	$	8.62	$	16.22	$	7.32


	Net income applicable to common stockholders per diluted common share	$	4.76	$	8.39	$	15.72	$	7.14

	_____________________________
	(1) As the Company's retail accommodation business, which recognizes revenue at the completion of the stay, continues to expand, our quarterly results become increasingly impacted by seasonal factors.

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS

	Acquisition activity in 2014

	OpenTable, Inc.

	On July 24, 2014, the Company acquired OpenTable, Inc., a leading online restaurant reservation business, in a cash transaction. The purchase price of OpenTable was approximately $2.5 billion (approximately $2.4 billion net of cash acquired) or $103.00 per share of OpenTable common stock. The Company funded the acquisition from cash on hand in the United States and $995 million borrowed under the Company's revolving credit facility, which the Company repaid during the third quarter of 2014 (see Note 11 for a description of the credit facility). Also, in connection with this acquisition, the Company assumed unvested employee stock options and restricted stock units with an acquisition fair value of approximately $95 million (see Note 3).

	OpenTable has built a strong brand helping diners secure restaurant reservations online at over 32,000 restaurants across the United States and select non-U.S. markets. OpenTable also helps restaurants manage their reservations and connect directly with their customers. The Company believes that OpenTable has significant global potential and intends to leverage its international experience and capabilities in support of OpenTable's international growth.

	The purchase price allocations were completed as of December 31, 2014. The aggregate purchase price was allocated to the assets acquired and liabilities assumed as follows (in millions):


	Current assets (1)	$	203

	Identifiable intangible assets (2)	1,435

	Goodwill (3)	1,500

	Other long-term assets	38

	Total liabilities (4)	(647		)
	Total consideration	$	2,529


	(1) Includes cash acquired of $126 million.
	(2) Acquired definite-lived intangibles, with a weighted average life of 18.8 years, consisted of trade names of $1.1 billion with an estimated useful life of 20 years, supply and distribution agreements of $290 million with an estimated useful life of 15 years, and technology of $15 million with estimated useful life of 5 years.
	(3) Goodwill is not tax deductible.
	(4) Includes deferred tax liabilities of $543 million.

	The Company's consolidated financial statements include the accounts of OpenTable starting on July 24, 2014. OpenTable's revenues and earnings since the acquisition date and pro forma results of operations have not been presented separately as such financial information is not material to the Company's results of operations.

	Other

	In the second quarter of 2014, the Company acquired certain businesses that provide hotel marketing services. The Company's consolidated financial statements include the accounts of these businesses starting at their respective acquisition dates. The Company paid approximately $98 million, net of cash acquired, to purchase these businesses. As of December 31, 2014, the Company recognized a liability of approximately $10.7 million for estimated contingent payments related to these acquisitions. The estimated contingent payments are based upon probability weighted average payments for specific performance factors from the acquisition dates through December 31, 2018. The range of undiscounted outcomes for the estimated contingent payments is approximately $0 to $71 million.

	The Company incurred $6.9 million of professional fees for the year ended December 31, 2014 related to these consummated acquisitions. These acquisition-related expenses were included in "General and administrative" expenses on the Consolidated Statements of Operations.

	Acquisition activity in 2013
	KAYAK Software Corporation

	On May 21, 2013, the Company acquired 100% of KAYAK Software Corporation in a stock and cash transaction. The purchase value was $2.1 billion ($1.9 billion net of cash acquired). The Company paid $0.5 billion in cash, from cash on hand in the United States, and $1.6 billion in shares of its common stock (based upon the market value of the Company's common stock at the merger date) and the fair value of the assumed vested KAYAK stock options. These assumed vested KAYAK stock options are related to pre-combination service. A significant amount of the aggregate purchase price was allocated to definite-lived intangibles and goodwill.

	Also in conjunction with the acquisition, the Company assumed unvested KAYAK employee stock options, which relate to post-combination service, with an acquisition date fair value of $57.4 million (see Note 3).
	As a result of the acquisition of KAYAK, the Company expensed approximately $8.5 million of professional fees for the year ended December 31, 2013. These acquisition-related expenses were included in "General and administrative" expenses on the Consolidated Statements of Operations. In addition, the Company paid approximately $1.2 million of stock issuance costs for the year ended December 31, 2013, with an offsetting charge to additional paid-in capital.

	The Company's consolidated financial statements include the accounts of KAYAK starting on May 21, 2013. KAYAK's revenues and earnings since the acquisition date and pro forma results of operations have not been presented as such financial information is not material to the Company's results of operations.

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Dec. 31, 2014
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates — The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the amounts reported in the financial statements and footnotes thereto. Actual results may differ significantly from those estimates. The estimates underlying the Company's Consolidated Financial Statements relate to, among other things, the accrual for travel transaction taxes, stock-based compensation, the allowance for doubtful accounts, the valuation of goodwill, long-lived assets and intangibles, income taxes, the accrual for loyalty programs and the valuation of redeemable noncontrolling interests.
Fair Value of Financial Instruments	Fair Value of Financial Instruments — The Company's financial instruments, including cash, restricted cash, accounts receivable, accounts payable, accrued expenses and deferred merchant bookings, are carried at cost which approximates their fair value because of the short-term nature of these financial instruments. See Notes 4, 5, 11 and 13 for information on fair value for investments, derivatives, the Company's outstanding Senior Notes and redeemable noncontrolling interests.
Cash and Cash Equivalents	Cash and Cash Equivalents — Cash and cash equivalents consists primarily of cash and highly liquid investment grade securities with an original maturity of three months or less.
Restricted Cash	Restricted Cash — Restricted cash at December 31, 2014 and 2013 collateralizes office leases and supplier obligations.
Investments	Investments — The Company has classified its investments as available-for-sale securities. These securities are carried at estimated fair value with the aggregate unrealized gains and losses related to these investments, net of taxes, reflected as a part of "Accumulated other comprehensive income (loss)" within stockholders' equity.

	The fair value of the investments is based on the specific quoted market price of the securities or comparable securities at the balance sheet dates. Investments in debt securities are considered to be impaired when a decline in fair value is judged to be other than temporary because the Company either intends to sell or it is more-likely-than not that it will have to sell the impaired security before recovery. Once a decline in fair value is determined to be other than temporary, an impairment charge is recorded and a new cost basis in the investment is established. If the Company does not intend to sell the debt security, but it is probable that the Company will not collect all amounts due, then only the impairment due to the credit risk would be recognized in earnings and the remaining amount of the impairment would be recognized in "Accumulated other comprehensive income (loss)" within stockholders' equity. Marketable securities are presented as current assets on the Company's Consolidated Balance Sheets if they are available to meet the short-term working capital needs of the Company. See Notes 4 and 5 for further detail of investments.
Property and Equipment	Property and Equipment — Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization of property and equipment is computed on a straight-line basis over the estimated useful lives of the assets or, when applicable, the life of the lease, whichever is shorter.
Website and Software Capitalization	Website and Software Capitalization — Certain direct development costs associated with website and internal-use software are capitalized and include external direct costs of services and payroll costs for employees devoting time to the software projects principally related to website and mobile app development, including support systems, software coding, designing system interfaces and installation and testing of the software. These costs are recorded as property and equipment and are generally amortized over a period of two to five years beginning when the asset is substantially ready for use. Costs incurred for enhancements that are expected to result in additional features or functionality are capitalized and amortized over the estimated useful life of the enhancements. Costs incurred during the preliminary project stage, as well as maintenance and training costs, are expensed as incurred.
Goodwill and Impairment of Long-Lived Assets and Intangible Assets	Goodwill — The Company accounts for acquired businesses using the purchase method of accounting which requires that the assets acquired and liabilities assumed be recorded at the date of acquisition at their respective fair values. Any excess of the purchase price over the estimated fair values of the net assets acquired is recorded as goodwill. The Company's Consolidated Financial Statements reflect an acquired business starting at the date of the acquisition.

	Goodwill is not subject to amortization and is reviewed at least annually for impairment, or earlier if an event occurs or circumstances change and there is an indication of impairment. The Company tests goodwill at a reporting unit level. The fair value of the reporting unit is compared to its carrying value, including goodwill. Fair values are determined based on discounted cash flows, market multiples or appraised values and are based on market participant assumptions. An impairment is recorded to the extent that the implied fair value of goodwill is less than the carrying value of goodwill. See Note 9 for further information.

	Impairment of Long-Lived Assets and Intangible Assets — The Company reviews long-lived assets and amortizable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. The assessment of possible impairment is based upon the Company's ability to recover the carrying value of the assets from the estimated undiscounted future net cash flows, before interest and taxes, of the related operations. The amount of impairment loss, if any, is measured as the excess of the carrying value of the asset over the present value of estimated future cash flows, using a discount rate commensurate with the risks involved and based on assumptions representative of market participants.
Revenue Recognition Policy	Agency Revenues

	Agency revenues are derived from travel-related transactions where the Company is not the merchant of record and where the prices of the services sold are determined by third parties. Agency revenues include travel commissions, global distribution system ("GDS") reservation booking fees and customer processing fees, and are reported at the net amounts received, without any associated cost of revenue. Such revenues are generally recognized by the Company when the customers complete their travel.

	Merchant Revenues and Cost of Merchant Revenues

	Merchant revenues and related cost of revenues are derived from services where the Company is the merchant of record and therefore charges the customer's credit card and subsequently pays the travel service provider for the services provided.

	Opaque Services: The Company describes its priceline.com Name Your Own Price® and Express Deals® travel services as "opaque" because certain elements of the service, including the identity of the travel service provider, are not disclosed to the consumer prior to making a reservation. The Name Your Own Price® service connects consumers that are willing to accept a level of flexibility regarding their travel itinerary with travel service providers that are willing to accept a lower price in order to sell their excess capacity without disrupting their existing distribution channels or retail pricing structures. The Company's Name Your Own Price® services use a unique pricing system that allows consumers to "bid" the price they are prepared to pay when submitting an offer for a particular leisure travel service. The Company accesses databases in which participating travel service providers file secure discounted rates, not generally available to the public, to determine whether it can fulfill the consumer's offer. The Company selects the travel service provider and determines the price it will accept from the consumer. Merchant revenues and cost of revenues include the selling price and cost, respectively, of the Name Your Own Price® travel services and are reported on a gross basis.



	In 2012, the Company launched Express Deals® as a merchant semi-opaque hotel reservation service at priceline.com. The Company has since expanded the Express Deals®service to include rental car and air reservation services. Express Deals® allows consumers to select hotel, car and air reservations with price and certain information regarding amenities disclosed prior to making the reservation. The identity of the travel service provider is not known prior to committing to the non-refundable reservation. The Company records the difference between the reservation price to the consumer and the travel service provider cost to the Company of its merchant Express Deals® reservation services on a net basis in merchant revenue.

	The Company recognizes revenues and costs for these services when it confirms the customer's non-refundable offer. In very limited circumstances, the Company makes certain customer concessions to satisfy disputes and complaints. The Company accrues for such estimated losses and classifies the resulting expense as adjustments to merchant revenue and cost of merchant revenues.

	Merchant Retail Services: Merchant revenues for the Company's merchant retail services are derived from transactions where consumers book accommodation reservations or rental car reservations from travel service providers at disclosed rates which are subject to contractual arrangements. Charges are billed to consumers by the Company at the time of booking and are included in deferred merchant bookings until the consumer completes the accommodation stay or returns the rental car. Such amounts are generally refundable upon cancellation, subject to cancellation penalties in certain cases. Merchant revenues and accounts payable to the travel service provider are recognized at the conclusion of the consumer's stay at the accommodation or return of the rental car. The Company records the difference between the reservation price to the consumer and the travel service provider cost to the Company of its merchant retail reservation services on a net basis in merchant revenue.

	Pursuant to the terms of the Company's opaque and retail merchant services, its travel service providers are permitted to bill the Company for the underlying cost of the service during a specified period of time. In the event that the Company is not billed by the travel provider within the specified time period, the Company reduces its cost of revenues by the unbilled amounts.

	Advertising and Other Revenues

	Advertising and other revenues are primarily earned by KAYAK and OpenTable. KAYAK earns advertising revenue primarily by sending referrals to travel service providers and OTAs and from advertising placements on its websites and mobile applications. Generally, revenue related to referrals is earned based upon the completion of travel by a consumer or when a consumer clicks on a referral placement and revenue for advertising placements is earned based upon when a customer clicks on an advertisement or when the Company displays an advertisement. OpenTable earns revenue primarily by facilitating reservations and providing computerized host-stand operations to restaurants through proprietary restaurant management reservation services. The Company recognizes other revenues related to OpenTable for reservation revenues when diners are seated and for subscription revenues on a straight-line basis during the contractual period over which the service is delivered. Revenues are recorded net of redeemable dining points issued to diners during each period presented.
Loyalty Programs	Loyalty Programs

	The Company provides various loyalty programs. Participating customers earn loyalty points on current transactions that can be redeemed for future qualifying transactions. When the points are earned, the Company estimates the amount of loyalty points expected to be redeemed and records a reduction in revenue. As of December 31, 2014, a liability of $71.1 million for loyalty points programs is included in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheet.
Tax Recovery Charge, Occupancy Taxes and State and Local Taxes	Tax Recovery Charge, Occupancy Taxes and State and Local Taxes

	The Company provides an online travel service to facilitate online travel purchases by consumers from travel service providers, including accommodation, rental car and airline ticket reservations, and sometimes as part of a vacation package reservation. For merchant model transactions, the Company charges the consumer an amount intended to cover the taxes that the Company anticipates the travel service provider will owe and remit to the local taxing authorities ("tax recovery charge"). Tax rate information for calculating the tax recovery charge is provided to the Company by the travel service providers.

	In certain taxing jurisdictions, the Company is required by passage of a new statute or by court order to collect and remit certain taxes (local occupancy tax, general excise and/or sales tax) imposed upon its margin and/or service fee, or in the case of Hawaii, on the full amount collected from the consumer. In those jurisdictions, the Company is collecting and remitting tax as required. The tax recovery charge and occupancy and other related taxes collected from customers and remitted to those jurisdictions are reported on a net basis on the Consolidated Statement of Operations. Except in those jurisdictions, the Company does not charge the customer or remit occupancy or other related taxes based on its margin or service fee, because the Company believes that such taxes are not owed on its compensation for its services (see Note 16).
Advertising - Online and Advertising - Offline	Advertising - Online — Online advertising expenses consist primarily of the costs of (1) search engine keyword purchases; (2) referrals from meta-search and travel research websites; (3) affiliate programs; and (4) banner, pop-up and other Internet and mobile advertisements. Online advertising expense is generally recognized as incurred. Included in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheets are accrued online advertising liabilities of $164.0 million and $130.3 million at December 31, 2014 and 2013, respectively.

	Advertising - Offline — Offline advertising expenses are primarily related to the Company's Booking.com, KAYAK and priceline.com businesses and primarily consist of television advertising. The Company expenses advertising production costs the first time the advertising is broadcast.
Sales and Marketing	Sales and Marketing — Sales and marketing expenses consist primarily of (1) credit card processing fees associated with merchant transactions; (2) fees paid to third parties that provide call center, website content translations and other services; (3) provisions for credit card chargebacks; and (4) provisions for bad debt, primarily related to agency accommodation commission receivables.
Personnel and Stock-Based Compensation	Personnel — Personnel expenses consist of compensation to the Company's personnel, including salaries, bonuses, stock-based compensation, payroll taxes and employee health benefits. Included in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheets are accrued compensation liabilities of $159.0 million and $142.7 million at December 31, 2014 and 2013, respectively.

	Stock-Based Compensation — The cost of stock-based compensatory transactions is recognized in the financial statements based upon fair value. The fair value of performance share units and restricted stock units is determined based on the number of units or shares, as applicable, granted and the quoted price of the Company's common stock as of the grant date or acquisition date. Stock-based compensation related to performance share units reflects the estimated probable outcome at the end of the performance period. The fair value of employee stock options assumed in acquisitions was determined using the Black Scholes model and the market value of the Company's common stock at the respective acquisition dates. Fair value is recognized as expense on a straight line basis, net of estimated forfeitures, over the employee requisite service period.

	The benefits of tax deductions in excess of recognized compensation costs are reported as a credit to additional paid-in capital and as financing cash flows, but only when such excess tax benefits are realized by a reduction to current taxes payable. See Note 3 for further information on stock-based awards.
Information Technology	Information Technology — Information technology expenses consist primarily of: (1) software license and system maintenance fees; (2) data communications and other expenses associated with operating our services; (3) outsourced data center costs; and (4) payments to outside consultants.
Income Taxes	Income Taxes — The Company accounts for income taxes under the asset and liability method. The Company records the estimated future tax effects of temporary differences between the tax bases of assets and liabilities and amounts reported on the Consolidated Balance Sheets, as well as operating loss and tax credit carryforwards. Deferred taxes are classified as current or noncurrent based on the balance sheet classification of the related assets and liabilities.

	The Company records deferred tax assets to the extent it believes these assets will more likely than not be realized. The Company regularly reviews its deferred tax assets for recoverability considering historical profitability, projected future taxable income, the expected timing of the reversals of existing temporary differences, the carryforward periods available for tax reporting purposes, and tax planning strategies. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The ultimate realization of deferred tax assets depends on the generation of future taxable income during the period in which related temporary differences become deductible. In determining the future tax consequences of events that have been recognized in the financial statements or tax returns, significant judgments, estimates, and interpretation of statutes are required.

	Deferred taxes are measured using the enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date of such change.

	Income taxes are not accrued for unremitted earnings of international operations that have been or are intended to be reinvested indefinitely.

	The Company recognizes liabilities when it believes that uncertain positions may not be fully sustained upon review by the tax authorities. Liabilities recognized for uncertain tax positions are based on a two step approach for recognition and measurement. First, the Company evaluates the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained on audit based on its technical merits. Secondly, the Company measures the tax benefit as the largest amount which is more than 50% likely of being realized upon ultimate settlement. Interest and penalties attributable to uncertain tax positions, if any, are recognized as a component of income tax expense. See Note 15 for further details on income taxes.
Segment Reporting	Segment Reporting — The Company determined that its brands constitute its operating segments. Based on similar economics characteristics and other similar operating factors, the Company has aggregated the operating segments into one reportable segment. The Company manages its business as one unit. For geographic related information, see Note 18.
Foreign Currency Translation	Foreign Currency Translation — The functional currency of the Company's foreign subsidiaries is generally their respective local currency. Assets and liabilities are translated into U.S. Dollars at the rate of exchange existing at the balance sheet date. Income statement amounts are translated at average monthly exchange rates applicable for the period. Translation gains and losses are included as a component of "Accumulated other comprehensive income (loss)" on the Company's Consolidated Balance Sheets. Foreign currency transaction gains and losses are included in "Foreign currency transactions and other" in the Company's Consolidated Statements of Operations.

	In September 2014, the Company issued Senior Notes due September 23, 2024 for an aggregate principal amount of 1.0 billion Euros and designated the carrying value, plus accrued interest, as a hedge of the Company's net investment in a Euro functional currency subsidiary. The foreign currency transaction gains or losses on these liabilities and the Euro denominated net assets of the subsidiary are translated into U.S. Dollars and are included as a component of "Accumulated other comprehensive income (loss)" on the Company's Consolidated Balance Sheet (see Notes 11 and 14).
Derivative Financial Instruments	Derivative Financial Instruments — As a result of the Company's international operations, it is exposed to various market risks that may affect its consolidated results of operations, cash flow and financial position. These market risks include, but are not limited to, fluctuations in currency exchange rates. The Company's primary foreign currency exposures are in Euros and British Pound Sterling, in which it conducts a significant portion of its business activities. As a result, the Company faces exposure to adverse movements in currency exchange rates as the financial results of its international operations are translated from local currency into U.S. Dollars upon consolidation. Additionally, foreign exchange rate fluctuations on transactions denominated in currencies other than the functional currency result in gains and losses that are reflected in income.

	The Company may enter into derivative instruments to hedge certain net exposures of nonfunctional currency denominated assets and liabilities and the volatility associated with translating earnings for its international businesses into U.S. Dollars, even though it does not elect to apply hedge accounting or hedge accounting does not apply. Gains and losses resulting from a change in fair value for these derivatives are reflected in income in the period in which the change occurs and are recognized on the Consolidated Statements of Operations in "Foreign currency transactions and other." Cash flows related to these contracts are classified within "Net cash provided by operating activities" on the cash flow statement.

	The Company, from time to time, utilizes derivative instruments to hedge the impact of changes in currency exchange rates on the net assets of its foreign subsidiaries. These instruments are designated as net investment hedges. Hedge ineffectiveness is assessed and measured based on changes in forward exchange rates. The Company records gains and losses on these derivative instruments as currency translation adjustments, which offset a portion of the translation adjustments related to the foreign subsidiary's net assets. Gains and losses are recognized on the Consolidated Balance Sheet in "Accumulated other comprehensive income (loss)" and will be realized upon a partial sale or liquidation of the investment. The Company formally documents all derivatives designated as hedging instruments for accounting purposes, both at hedge inception and on an on-going basis. These net investment hedges expose the Company to liquidity risk as the derivatives have an immediate cash flow impact upon maturity, which is not offset by the translation of the underlying hedged equity. The cash flows from these contracts are classified within "Net cash used in investing activities" on the cash flow statement.

	The Company does not use financial instruments for trading or speculative purposes. The Company recognizes all derivative instruments on the balance sheet at fair value and its derivative instruments are generally short-term in duration. The derivative instruments do not contain leverage features.

	The Company is exposed to the risk that counterparties to derivative contracts may fail to meet their contractual obligations. The Company regularly reviews its credit exposure as well as assessing the creditworthiness of its counterparties. See Note 5 for further detail on derivatives.
Recent Accounting Pronouncements	Recent Accounting Pronouncements

	In May 2014, the Financial Accounting Standards Board ("FASB") and the International Accounting Standards Board ("IASB") issued a new accounting standard on the recognition of revenue from contracts with customers that is designed to create greater comparability for financial statement users across industries and jurisdictions. The core principle of the standard is that an "entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services." Additionally, the new guidance specifies the accounting for some costs to obtain or fulfill a contract with a customer. The new standard will also require enhanced disclosures. The accounting standard is effective for public entities for annual and interim periods beginning after December 15, 2016. Early adoption is not permitted under U.S. GAAP and retrospective application is permitted but not required. The Company is currently evaluating the impact on its consolidated financial statements of adopting this new guidance.
	In April 2014, the FASB issued an accounting update which amends the definition of a discontinued operation. The new definition limits discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have or will have a major effect on an entity's operations and financial results. The new definition includes an acquired business that is classified as held for sale at the date of acquisition. The accounting update requires new disclosures of both discontinued operations and a disposal of an individually significant component of an entity. The accounting update is effective for annual and interim periods beginning on or after December 15, 2014. Early adoption is permitted but only for disposals that have not been reported in financial statements previously issued. The Company adopted this update in the first quarter of 2015 and this accounting update did not have an impact on the Company's consolidated financial statements.
	In July 2013, the FASB issued an accounting update which provides guidance on financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward or a tax credit carryforward exists in the same taxing jurisdiction. Per this guidance, an entity must present the unrecognized tax benefit as a reduction to a deferred tax asset, except when the carryforward is not available as of the reporting date under the governing tax law to settle taxes or the entity does not intend to use the deferred tax asset for this purpose. This amendment does not impact the recognition or measurement of uncertain tax positions or the disclosure reconciliation of gross unrecognized tax benefits. The update is effective for public companies beginning after December 15, 2013. The Company adopted this update in the first quarter of 2014 and this accounting update did not have an impact on the Company's consolidated balance sheet.
	In February 2013, the FASB issued accounting guidance which requires entities to provide additional information about items reclassified out of accumulated other comprehensive income ("AOCI") to net income. Changes in AOCI balances by component, both before tax and after tax, must be disclosed and significant items reclassified out of AOCI by component must be reported either on the face of the income statement or in a separate footnote to the financial statements. The accounting guidance is effective for public companies for fiscal years, and interim periods within those years, beginning after December 15, 2012. See Note 14 for information on AOCI balances. There were no reclassifications out of AOCI to net income for the years ended December 31, 2014, 2013 and 2012.
	On January 1, 2012, the Company adopted the amended accounting guidance issued by the Financial Accounting Standards Board ("FASB") concerning the presentation of comprehensive income. The new guidance requires comprehensive income to be reported in either a single statement or in two consecutive statements reporting net income and other comprehensive income. The Company selected to present two consecutive statements. This amended guidance did not change the items that constitute net income or other comprehensive income, the timing of when other comprehensive income is reclassified to net income, or the earnings per share computation.

	In September 2011, the FASB issued an accounting update, which amended the guidance on testing goodwill for impairment. Under the revised guidance, entities testing goodwill for impairment have the option of performing a qualitative assessment before calculating the fair value of the reporting unit. If, based on the qualitative factors, it is more-likely-than not that the fair value of the reporting unit is less than its carrying value, then the unchanged two-step approach previously used would be required. The new accounting guidance did not change how goodwill is calculated, how goodwill is assigned to the reporting unit, or the requirements for testing goodwill annually or when events and circumstances warrant testing. The accounting update was effective for annual and interim periods beginning after December 15, 2011, with early adoption permitted. In September 2014, the Company performed its annual quantitative goodwill impairment testing and concluded that there was no impairment of goodwill.

	In May 2010, the FASB issued amended guidance on fair value to largely achieve common fair value measurement and disclosure requirements between U.S. GAAP and IFRS. The new accounting guidance did not extend the use of fair value but rather provided guidance about how fair value should be determined. For U.S. GAAP, most of the changes were clarifications of existing guidance or wording changes to align with IFRS. The amended guidance expanded disclosure, particularly that relating to fair value measurements based on unobservable inputs, permitted fair value measurements for financial assets and liabilities on a net position if market or credit risks are managed on a net basis and other criteria are met, and allowed premiums and discounts only if a market participant would also include them in the fair value measurement. This accounting update was effective for public companies for interim or annual periods beginning after December 15, 2011, with early adoption permitted. The adoption of this accounting guidance, effective with the three months ended March 31, 2012, did not impact the Company's consolidated financial statements or disclosure.

STOCKBASED_COMPENSATION_Tables

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Activity of unvested restricted stock units and performance share units	The following table summarizes the activity of unvested restricted stock units ("RSUs") and performance share units during the years ended December 31, 2012, 2013 and 2014:



	Share-Based Awards	Shares		Weighted Average Grant
				Date Fair Value

	Unvested at December 31, 2011	799,980			$	231.87


	Granted	95,062			$	643.12

	Vested	(353,819	)		$	108.31

	Performance Shares Adjustment	6,649			$	532.26

	Forfeited	(7,744	)		$	444.18

	Unvested at December 31, 2012	540,128			$	389.21


	Granted	162,341			$	730.47

	Vested	(258,198	)		$	242.63

	Performance Shares Adjustment	101,490			$	681.13

	Forfeited	(11,442	)		$	579.71

	Unvested at December 31, 2013	534,319			$	615.1


	Granted	128,484			$	1,308.13

	Assumed in an acquisition	43,993			$	1,238.68

	Vested	(195,730	)		$	492.22

	Performance Shares Adjustment	68,499			$	1,085.94

	Forfeited	(9,250	)		$	972.19

	Unvested at December 31, 2014	570,315			$	912.26

Schedule of share-based compensation, stock options, activity	The following table summarizes for the year ended December 31, 2014 stock option activity for employee stock options assumed in acquisitions:


	Assumed Employee Stock Options		Number of Shares			Weighted Average			Aggregate			Weighted Average Remaining Contractual Term (in years)
						Exercise Price			Intrinsic Value (000's)
	Balance, January 1, 2013		—				$	—		$	—	0

	Assumed in acquisition		540,179				$	260.96

	Exercised		(387,669	)			$	222.73

	Forfeited		(23,802	)			$	478.83

	Balance, December 31, 2013		128,708				$	335.83		$	106,386	6.9

	Assumed in acquisitions		61,897				$	457.67

	Exercised		(43,223	)			$	342.39

	Forfeited		(2,217	)			$	517.91

	Balance, December 31, 2014		145,165				$	383.05		$	109,914	6.5

	Vested and exercisable as of December 31, 2014		88,118				$	306.32		$	73,481	5.7

	Vested and exercisable as of December 31, 2014 and expected to vest thereafter, net of estimated forfeitures		144,077				$	382.81		$	109,124	6.5

INVESTMENTS_Tables

INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Investments	The following table summarizes, by major security type, the Company's investments as of December 31, 2014 (in thousands):



		Cost		Gross		Gross			Fair Value
				Unrealized		Unrealized
				Gains		Losses
	Available for sale securities:
	Short-term investments:
	Foreign government securities	$	52,524	$	—	$	(34	)	$	52,490

	U.S. government securities	364,276		24		(34		)	364,266

	U.S. commercial paper	621,252		15		(652		)	620,615

	U.S. government agency securities	104,829		—		(18		)	104,811

	Total short-term investments	$	1,142,881	$	39	$	(738	)	$	1,142,182


	Long-term investments:
	Foreign government securities	$	12,707	$	—	$	(36	)	$	12,671

	U.S. government securities	557,130		80		(762		)	556,448

	U.S. corporate debt securities	2,332,030		2,299		(5,296		)	2,329,033

	U.S. government agency securities	95,108		97		(111		)	95,094

	U.S. municipal securities	1,114		—		(12		)	1,102

	Ctrip corporate debt securities	500,000		—		(74,039		)	425,961

	Ctrip equity securities	421,930		—		(86,586		)	335,344

	Total long-term investments	$	3,920,019	$	2,476	$	(166,842	)	$	3,755,653

	The following table summarizes, by major security type, the Company's short-term investments as of December 31, 2013 (in thousands):



		Cost		Gross		Gross			Fair Value
				Unrealized		Unrealized
				Gains		Losses
	Available for sale securities:
	Short-term investments:
	Foreign government securities	$	4,019,530	$	233	$	(356	)	$	4,019,407

	U.S. government securities	1,443,083		250		(20		)	1,443,313

	Total	$	5,462,613	$	483	$	(376	)	$	5,462,720

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Financial instruments carried at fair value	Financial assets and liabilities are carried at fair value as of December 31, 2014 and are classified in the categories described in the tables below (in thousands):



			Level 1			Level 2			Total
	ASSETS:
	Cash equivalents:
	Money market funds		$	155,608		$	—		$	155,608

	Foreign government securities		—			974,855			974,855

	U.S. government securities		—			676,503			676,503

	U.S. commercial paper		—			427,884			427,884

	U.S. government agency securities		—			10,000			10,000

	Short-term investments:
	Foreign government securities		—			52,490			52,490

	U.S. government securities		—			364,266			364,266

	U.S. commercial paper		—			620,615			620,615

	U.S. government agency securities		—			104,811			104,811

	Foreign exchange derivatives		—			336			336

	Long-term investments:
	Foreign government securities		—			12,671			12,671

	U.S. government securities		—			556,448			556,448

	U.S. corporate debt securities		—			2,329,033			2,329,033

	U.S. government agency securities		—			95,094			95,094

	U.S. municipal securities		—			1,102			1,102

	Ctrip corporate debt securities		—			425,961			425,961

	Ctrip equity securities		335,344			—			335,344

	Total assets at fair value		$	490,952		$	6,652,069		$	7,143,021




			Level 1			Level 2			Total
	LIABILITIES:
	Foreign exchange derivatives		$	—		$	129		$	129


	Financial assets and liabilities are carried at fair value as of December 31, 2013 and are classified in the categories described in the tables below (in thousands):



			Level 1			Level 2			Total
	ASSETS:

	Cash equivalents:
	Money market funds		$	433,850		$	—		$	433,850

	Foreign government securities		—			238,202			238,202

U.S. government securities		—			28,000			28,000

Short-term investments:

Foreign government securities		—			4,019,407			4,019,407

U.S. government securities		—			1,443,313			1,443,313

Foreign exchange derivatives		—			292			292

Total assets at fair value		$	433,850		$	5,729,214		$	6,163,064




		Level 1			Level 2			Total
LIABILITIES:

Foreign exchange derivatives		$	—		$	122,091		$	122,091

ACCOUNTS_RECEIVABLE_RESERVES_T

ACCOUNTS RECEIVABLE RESERVES (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Changes in accounts receivable reserves	Changes in accounts receivable reserves consisted of the following (in thousands):



		For the Year Ended December 31,
		2014			2013			2012
	Balance, beginning of year	$	14,116		$	10,322		$	6,103

	Provision charged to expense	22,990			16,451			16,094

	Charge-offs and adjustments	(21,546		)	(13,072		)	(11,977		)
	Currency translation adjustments	(1,348		)	415			102

	Balance, end of year	$	14,212		$	14,116		$	10,322

NET_INCOME_PER_SHARE_Tables

NET INCOME PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Reconciliation of the weighted average number of shares outstanding used in calculating diluted earnings per share	A reconciliation of the weighted average number of shares outstanding used in calculating diluted earnings per share is as follows (in thousands):



		For the Year Ended December 31,
		2014	2013	2012
	Weighted average number of basic common shares outstanding	52,301	50,924	49,840

	Weighted average dilutive stock options, restricted stock units and performance share units	340	382	501

	Assumed conversion of Convertible Senior Notes	382	1,107	985

	Weighted average number of diluted common and common equivalent shares outstanding	53,023	52,413	51,326

	Anti-dilutive potential common shares	2,574	2,384	2,202

PROPERTY_AND_EQUIPMENT_Tables

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and equipment	Property and equipment at December 31, 2014 and 2013 consisted of the following (in thousands):



		2014			2013			Estimated
								Useful Lives
								(years)
	Computer equipment and software	$	332,650		$	244,845		2 to 5

	Office equipment, furniture, fixtures & leasehold improvements	110,297			67,942			2 to 11

	Total	442,947			312,787

	Less: accumulated depreciation and amortization	(243,994		)	(177,734		)
	Property and equipment, net	$	198,953		$	135,053

INTANGIBLE_ASSETS_AND_GOODWILL1

INTANGIBLE ASSETS AND GOODWILL (Tables)	12 Months Ended
INTANGIBLE ASSETS AND GOODWILL (Tables)	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets	The Company's intangible assets at December 31, 2014 and 2013 consisted of the following (in thousands):



		December 31, 2014								December 31, 2013
		Gross Carrying			Accumulated			Net Carrying		Gross Carrying		Accumulated			Net Carrying		Amortization	Weighted Average Useful
		Amount			Amortization			Amount		Amount		Amortization			Amount		Period	Life

	Supply and distribution agreements	$	842,642		$	(188,441	)	$	654,201	$	581,742	$	(160,499	)	$	421,243	10 - 20 years	16 years
	Supply and distribution agreements	$	842,642		$	(188,441	)	$	654,201	$	581,742	$	(160,499	)	$	421,243	10 - 20 years	16 years

	Technology	108,987			(43,746		)	65,241		93,322		(29,271		)	64,051		1 - 5 years	5 years
	Technology	108,987			(43,746		)	65,241		93,322		(29,271		)	64,051		1 - 5 years	5 years

	Patents	1,623			(1,524		)	99		1,623		(1,478		)	145		15 years	15 years
	Patents	1,623			(1,524		)	99		1,623		(1,478		)	145		15 years	15 years

	Internet domain names	41,652			(16,895		)	24,757		45,799		(12,112		)	33,687		2 - 20 years	8 years
	Internet domain names	41,652			(16,895		)	24,757		45,799		(12,112		)	33,687		2 - 20 years	8 years

	Trade names	1,674,218			(100,850		)	1,573,368		548,243		(47,388		)	500,855		5 - 20 years	20 years
	Trade names	1,674,218			(100,850		)	1,573,368		548,243		(47,388		)	500,855		5 - 20 years	20 years

	Non-compete agreements	21,000			(3,908		)	17,092		—		—			—		3 years	3 years
	Non-compete agreements	21,000			(3,908		)	17,092		—		—			—		3 years	3 years

	Other	141			(138		)	3		141		(137		)	4		3 - 10 years	3 years
	Other	141			(138		)	3		141		(137		)	4		3 - 10 years	3 years
	Total intangible assets	$	2,690,263		$	(355,502	)	$	2,334,761	$	1,270,870	$	(250,885	)	$	1,019,985
	Total intangible assets	$	2,690,263		$	(355,502	)	$	2,334,761	$	1,270,870	$	(250,885	)	$	1,019,985
Annual estimated amortization expense for intangible assets for the next five years and thereafter	The annual estimated amortization expense for intangible assets for the next five years and thereafter is expected to be as follows (in thousands):



	2015	$	171,007
	2015	$	171,007
	2016	167,887
	2016	167,887
	2017	160,296
	2017	160,296
	2018	141,776
	2018	141,776
	2019	131,727
	2019	131,727
	Thereafter	1,562,068
	Thereafter	1,562,068
		$	2,334,761
		$	2,334,761
Goodwill	A roll-forward of goodwill for the years ended December 31, 2014 and 2013 consisted of the following (in thousands):



		2014			2013
	Balance, beginning of year	$	1,767,912		$	522,672
	Balance, beginning of year	$	1,767,912		$	522,672
	Acquisitions	1,590,829			1,232,342
	Acquisitions	1,590,829			1,232,342
	Currency translation adjustments	(32,267		)	12,898
	Currency translation adjustments	(32,267		)	12,898
	Balance, end of year	$	3,326,474		$	1,767,912
	Balance, end of year	$	3,326,474		$	1,767,912

OTHER_ASSETS_Tables

OTHER ASSETS (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, All Other Investments [Abstract]
Components of other assets	Other assets at December 31, 2014 and 2013 consisted of the following (in thousands):



		2014		2013
	Deferred debt issuance costs	$	27,204	$	16,465

	Security deposits	12,368		10,617

	Deferred tax assets	8,548		7,055

	Other	9,228		6,432

	Total	$	57,348	$	40,569

DEBT_Tables

DEBT (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Schedule of convertible debt	Outstanding debt as of December 31, 2014 consisted of the following (in thousands):



	December 31, 2014	Outstanding		Unamortized			Carrying
		Principal		Debt			Value
		Amount		Discount
	Short-term debt:
	1.25% Convertible Senior Notes due March 2015	$	37,524	$	(329	)	$	37,195


	Long-term debt:
	1.0% Convertible Senior Notes due March 2018	$	1,000,000	$	(74,834	)	$	925,166

	0.35% Convertible Senior Notes due June 2020	1,000,000		(138,114		)	861,886

	0.9% Convertible Senior Notes due September 2021	1,000,000		(136,299		)	863,701

	2.375% (€1 Billion) Senior Notes due September 2024	1,210,068		(11,065		)	1,199,003

	Total long-term debt	$	4,210,068	$	(360,312	)	$	3,849,756


	Outstanding debt as of December 31, 2013 consisted of the following (in thousands):



	December 31, 2013	Outstanding		Unamortized			Carrying
		Principal		Debt			Value
		Amount		Discount
	Short-term debt:
	1.25% Convertible Senior Notes due March 2015	$	160,464	$	(8,533	)	$	151,931


	Long-term debt:
	1.0% Convertible Senior Notes due March 2018	$	1,000,000	$	(96,797	)	$	903,203

	0.35% Convertible Senior Notes due June 2020	1,000,000		(161,156		)	838,844

	Total long-term debt	$	2,000,000	$	(257,953	)	$	1,742,047

REDEEMABLE_NONCONTROLLING_INTE1

REDEEMABLE NONCONTROLLING INTERESTS (Tables)	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Reconciliation of redeemable noncontrolling interests	A reconciliation of redeemable noncontrolling interests for the years ended December 31, 2013 and 2012 is as follows (in thousands):



		2013			2012
	Balance, beginning of period	$	160,287		$	127,045

	Net income attributable to noncontrolling interests	135			4,471

	Fair value adjustments(1)	42,522			84,693

	Purchase of subsidiary shares at fair value(1)	(192,530		)	(61,079		)
	Currency translation adjustments	(10,414		)	5,157

	Balance, end of period	$	—		$	160,287

	_____________________________
	(1) The fair value of the redeemable noncontrolling interests was determined by industry peer comparable analysis and a discounted cash flow valuation model.

ACCUMULATED_OTHER_COMPREHENSIV1

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	12 Months Ended
	Dec. 31, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Balances for each classification of accumulated other comprehensive income (loss)	The table below provides the balances for each classification of accumulated other comprehensive income (loss) as of December 31, 2014 and 2013 (in thousands):



		December 31, 2014			December 31, 2013
	Foreign currency translation adjustments, net of tax (1)	$	(102,758	)	$	84,598

	Net unrealized gain (loss) on investment securities, net of tax (2)	(157,144		)	131

	Accumulated other comprehensive income (loss)	$	(259,902	)	$	84,729

	_____________________________
	(1) Foreign currency translation adjustments, net of tax, includes net losses from fair value adjustments at December 31, 2014 of $37.8 million after tax ($57.8 million before tax) and a net losses from fair value adjustments at December 31, 2013 of $58.7 million after tax ($98.8 million before tax) associated with derivatives designated as net investment hedges (see Note 5).

	Foreign currency translation adjustments, net of tax, includes foreign currency transaction gains at December 31, 2014 of $48.3 million after tax ($83.8 million before tax) associated with the Company's 2024 Notes, which are Euro denominated debt, designated as a net investment hedge (see Note 11).

	The remaining balance in currency translation adjustments excludes income taxes as a result of the Company's intention to indefinitely reinvest the earnings of its non-U.S. subsidiaries outside of the United States.

	(2) The unrealized loss before tax at December 31, 2014 was $164.7 million compared to an unrealized gain before tax at December 31, 2013 of $0.2 million.

INCOME_TAXES_Tables

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	The income tax expense (benefit) for the year ended December 31, 2014 is as follows (in thousands):



		Current			Deferred			Total
	International	$	496,719		$	(10,613	)	$	486,106

	U.S. Federal	10,316			47,847			58,163

	U.S. State	28,953			(5,527		)	23,426

	Total	$	535,988		$	31,707		$	567,695


	The income tax expense (benefit) for the year ended December 31, 2013 is as follows (in thousands):



		Current			Deferred			Total
	International	$	396,162		$	(16,314	)	$	379,848

	U.S. Federal	5,250			11,454			16,704

	U.S. State	13,431			(6,244		)	7,187

	Total	$	414,843		$	(11,104	)	$	403,739


	The income tax expense (benefit) for the year ended December 31, 2012 is as follows (in thousands):



		Current			Deferred			Total
	International	$	302,352		$	(13,792	)	$	288,560

	U.S. Federal	3,681			37,956			41,637

	U.S. State	12,203			(4,568		)	7,635

	Total	$	318,236		$	19,596		$	337,832

Tax effects of temporary differences that give rise to significant portions of deterred tax assets and liabilities	The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities at December 31, 2014 and 2013 are as follows (in thousands):



		2014			2013
	Deferred tax assets/(liabilities):

	Net operating loss carryforward — U.S.	$	176,786		$	263,994

	Net operating loss carryforward — International	22,353			21,660

	Fixed assets	—			818

	Accrued expenses	41,117			22,708

	Stock-based compensation and other stock based payments	54,935			40,346

	Other	24,456			33,530

	Subtotal	319,647			383,056


	Discount on convertible notes	(141,193		)	(97,550		)
	Intangible assets and other	(856,807		)	(356,669		)
	Euro denominated debt	(35,441		)	—

	Fixed assets	(3,409		)	—

	Less valuation allowance on deferred tax assets	(161,997		)	(173,558		)
	Net deferred tax assets (liabilities)(1)	$	(879,200	)	$	(244,721	)

	(1) Includes non-current deferred tax assets of $8.5 million and $7.1 million as of December 31, 2014 and 2013, respectively, reported in "Other assets" on the Consolidated Balance Sheets and current deferred tax liabilities of $1.2 million and $38 thousand as of December 31, 2014 and 2013, respectively, reported in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheets.
Schedule of effective income tax rate reconciliation	The effective income tax rate of the Company is different from the amount computed using the expected U.S. statutory federal rate of 35% as a result of the following items (in thousands):



		2014			2013			2012
	Income tax expense at federal statutory rate	$	1,046,307		$	803,788		$	616,654

	Adjustment due to:

	Foreign rate differential	(289,692		)	(226,894		)	(175,932		)
	Innovation Box Tax benefit	(233,545		)	(177,195		)	(118,916		)
	Other	44,625			4,040			16,026

	Income tax expense	$	567,695		$	403,739		$	337,832

Reconciliation of unrecognized tax benefits	The following is a reconciliation of the total amount of unrecognized tax benefits (in thousands):



		2014			2013			2012
	Unrecognized tax benefit — January 1	$	22,104		$	7,343		$	3,192

	Gross increases — tax positions in current period	9,305			8,597			4,423

	Gross increases — tax positions in prior periods	6,569			3,507			343

	Increase acquired in business combination	17,767			7,089			—

	Gross decreases — tax positions in prior periods	(2,164		)	(495		)	(615		)
	Reduction due to lapse in statute of limitations	(346		)	(3,937		)	—

	Reduction due to settlements during the current period	(879		)	—			—

	Unrecognized tax benefit — December 31	$	52,356		$	22,104		$	7,343

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Minimum payments for operating leases	Minimum payments for operating leases for office space, data centers and equipment having initial or remaining non-cancellable terms in excess of one year have been translated into U.S. Dollars at the December 31, 2014 spot exchange rates, as applicable, and are as follows (in thousands):



	2015	2016	2017	2018	2019	After	Total
						2019
	$79,902	$73,853	$59,583	$50,239	$42,918	$130,891	$437,386

GEOGRAPHIC_INFORMATION_Tables

GEOGRAPHIC INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Geographic Information	The Company's geographic information is as follows (in thousands):



		United		The		Other		Total
		States		Netherlands				Company
	2014

	Revenues	$	1,798,484	$	5,519,207	$	1,124,280	$	8,441,971

	Intangible assets, net	2,183,957		108,650		42,154		2,334,761

	Goodwill	2,712,479		224,731		389,264		3,326,474

	Other long-lived assets	80,668		97,056		77,915		255,639


	2013

	Revenues	$	1,769,696	$	4,103,393	$	920,217	$	6,793,306

	Intangible assets, net	838,494		123,847		57,644		1,019,985

	Goodwill	1,247,686		156,261		363,965		1,767,912

	Other long-lived assets	49,750		61,164		64,708		175,622


	2012

	Revenues	$	1,661,710	$	2,675,976	$	923,270	$	5,260,956

	Intangible assets, net	1,337		137,255		69,521		208,113

	Goodwill	37,306		149,464		335,902		522,672

	Other long-lived assets	76,623		37,035		42,924		156,582

SELECTED_QUARTERLY_FINANCIAL_D1

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Selected quarterly financial data (unaudited)

		First		Second		Third		Fourth
		Quarter		Quarter		Quarter		Quarter
		(In thousands, except per share data)

	2014


	Total revenues(1)	$	1,641,802	$	2,123,575	$	2,836,497	$	1,840,097


	Gross profit	1,406,471		1,882,996		2,619,978		1,674,685


	Net income	331,218		576,451		1,062,253		451,831


	Net income applicable to common stockholders	331,218		576,451		1,062,253		451,831


	Net income applicable to common stockholders per basic common share	$	6.35	$	11	$	20.27	$	8.65


	Net income applicable to common stockholders per diluted common share	$	6.25	$	10.89	$	20.03	$	8.56





		First		Second		Third		Fourth
		Quarter		Quarter		Quarter		Quarter
		(In thousands, except per share data)

	2013


	Total revenues(1)	$	1,302,012	$	1,680,238	$	2,269,903	$	1,541,153


	Gross profit	1,009,665		1,383,855		1,989,065		1,333,301


	Net income	244,292		437,440		832,989		378,077


	Net income applicable to common stockholders	244,271		437,326		832,989		378,077


	Net income applicable to common stockholders per basic common share	$	4.89	$	8.62	$	16.22	$	7.32


	Net income applicable to common stockholders per diluted common share	$	4.76	$	8.39	$	15.72	$	7.14

	_____________________________
	(1) As the Company's retail accommodation business, which recognizes revenue at the completion of the stay, continues to expand, our quarterly results become increasingly impacted by seasonal factors.

ACQUISITIONS_Tables

ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Schedule of Purchase Price Allocation	The purchase price allocations were completed as of December 31, 2014. The aggregate purchase price was allocated to the assets acquired and liabilities assumed as follows (in millions):


	Current assets (1)	$	203

	Identifiable intangible assets (2)	1,435

	Goodwill (3)	1,500

	Other long-term assets	38

	Total liabilities (4)	(647		)
	Total consideration	$	2,529


	(1) Includes cash acquired of $126 million.
	(2) Acquired definite-lived intangibles, with a weighted average life of 18.8 years, consisted of trade names of $1.1 billion with an estimated useful life of 20 years, supply and distribution agreements of $290 million with an estimated useful life of 15 years, and technology of $15 million with estimated useful life of 5 years.
	(3) Goodwill is not tax deductible.
	(4) Includes deferred tax liabilities of $543 million.

SUMMARY_OF_SIGNIFICANT_ACCOUNT2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Sep. 30, 2014
In Millions, unless otherwise specified	USD ($)	USD ($)	Website and software	Website and software	2.375% Senior Notes Due September 2024	2.375% Senior Notes Due September 2024
			Minimum	Maximum	EUR (€)	EUR (€)
Accounting Policies [Abstract]
Customer Loyalty Program Liability, Current	$71.10
Accrued online advertising liabilities	164	130.3
Accrued compensation liabilities	159	142.7
Debt Instrument, Face Amount					€ 1,000	€ 1,000
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)			2 years	5 years

STOCKBASED_COMPENSATION_Narrat

STOCK-BASED COMPENSATION (Narrative) (Details) (USD $)	12 Months Ended			7 Months Ended
STOCK-BASED COMPENSATION (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$186,425,000	$140,526,000	$71,565,000
Share-based compensation, cumulative charges for adjustment of the estimated probable outcome on unvested performance awards	20,600,000	24,100,000	900,000
Stock-based compensation cost, non-employee directors	2,300,000	2,100,000	1,800,000
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	38,400,000	18,500,000	7,600,000
Exercised (in shares)	-7,780
Exercised (in dollars per share)	$22.47
Balance, (in shares)	1,220
Weighted Average Exercise Price (in dollars per share)	$23.08
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	6 months
Aggregate intrinsic value	1,400,000
Stock options exercised, total intrinsic value	9,300,000	44,900,000	75,200,000
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant term (in years)	10 years
Awards Other Than Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units and performance share units aggregate grant-date fair value	168,100,000	118,600,000	61,100,000	118,600,000
Aggregate grant-date fair value of restricted shares, performance share units and restricted stock units vested during the period	96,300,000	62,600,000	38,300,000
Total future compensation cost related to unvested share-based awards	263,800,000
Total future compensation cost related to unvested share-based awards, expected period of recognition	1 year 8 months
Granted (in shares)	128,484	162,341	95,062
Granted (in dollars per share)	$1,308.13	$730.47	$643.12
Unvested at (in shares)	570,315	534,319	540,128	534,319	799,980
Performance Share Units 2014 Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	72,277
Grant date fair value	96,100,000
Granted (in dollars per share)	$1,329.11
Unvested at (in shares)	72,098
Estimated number of probable shares to be issued (in shares)	109,618
Maximum shares that could be issued (in shares)	145,981
Minimum shares that could be issued (in shares)	50,884
Performance Share Units 2013 Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		104,865
Grant date fair value		74,400,000
Granted (in dollars per share)		$709.74
Unvested at (in shares)	102,816
Estimated number of probable shares to be issued (in shares)	197,225
Maximum shares that could be issued (in shares)	225,202
Minimum shares that could be issued (in shares)	40,120
Performance Share Units 2012 Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			60,365
Grant date fair value			39,000,000
Granted (in dollars per share)			$645.86
Unvested at (in shares)	57,571
Estimated number of probable shares to be issued (in shares)	100,190
1999 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available to be issued under the plan (in shares)	2,650,485
KAYAK 2012 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available to be issued under the plan (in shares)	14,351
Buuteeq, Inc. Amended and Restated 2010 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available to be issued under the plan (in shares)	191
OpenTable 2009 Equity Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available to be issued under the plan (in shares)	238,804
Minimum \| Awards Other Than Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Maximum \| Awards Other Than Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
Assumed in an acquisition \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	24,700,000			30,900,000
Total future compensation cost related to unvested share-based awards, expected period of recognition	1 year 7 months
Stock-based compensation expense, not yet recognized	36,200,000
Exercised (in shares)	-43,223	-387,669
Exercised (in dollars per share)	$342.39	$222.73
Balance, (in shares)	145,165	128,708	0	128,708
Weighted Average Exercise Price (in dollars per share)	$383.05	$335.83	$0	$335.83
Weighted Average Remaining Contractual Term	5 years 8 months
Aggregate intrinsic value	109,914,000	106,386,000	0	106,386,000
Stock options exercised, total intrinsic value	39,900,000			236,900,000
Acquisition date fair value of assumed options	45,500,000
Acquisition date fair value per share of assumed stock options	$734.76
Assumed unvested employee stock options vesting during period (in shares)	41,524			65,293
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	$24,200,000			$30,900,000

STOCKBASED_COMPENSATION_Restri

STOCK-BASED COMPENSATION (Restricted Stock Units and Performance Share Units) (Details) (Awards Other Than Options, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-Based Awards - Shares
Unvested at (in shares)	534,319	540,128	799,980
Granted (in shares)	128,484	162,341	95,062
Vested (in shares)	-195,730	-258,198	-353,819
Performance Shares Adjustment (in shares)	68,499	101,490	6,649
Forfeited (in shares)	-9,250	-11,442	-7,744
Unvested at (in shares)	570,315	534,319	540,128
Share-Based Awards - Weighted Average Grant Date Fair Value
Unvested at (in dollars per share)	$615.10	$389.21	$231.87
Granted (in dollars per share)	$1,308.13	$730.47	$643.12
Vested (in dollars per share)	$492.22	$242.63	$108.31
Performance Shares Adjustment (in dollars per share)	$1,085.94	$681.13	$532.26
Forfeited (in dollars per share)	$972.19	$579.71	$444.18
Unvested at (in dollars per share)	$912.26	$615.10	$389.21
Assumed in an acquisition
Share-Based Awards - Shares
Assumed in acquisition (in shares)	43,993
Share-Based Awards - Weighted Average Grant Date Fair Value
Assumed in acquisition (in dollars per share)	$1,238.68

STOCKBASED_COMPENSATION_Schedu

STOCK-BASED COMPENSATION (Schedule of Assumed Stock Options) (Details) (USD $)	7 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Number of Shares
Exercised (in shares)		-7,780
Balance, (in shares)		1,220
Weighted Average Exercise Price
Exercised (in dollars per share)		$22.47
Balance, (in dollars per share)		$23.08
Aggregate Intrinsic Value		$1,400
Employee Stock Option \| Assumed in an acquisition
Number of Shares
Balance, (in shares)		128,708	0
Assumed in acquisitions (in shares)		61,897	540,179
Exercised (in shares)		-43,223	-387,669
Forfeited (in shares)		-2,217	-23,802
Balance, (in shares)	128,708	145,165	128,708	0
Weighted Average Exercise Price
Balance, (in dollars per share)		$335.83	$0
Assumed in acquisitions (in dollars per share)		$457.67	$260.96
Exercised (in dollars per share)		$342.39	$222.73
Forfeited (in dollars per share)		$517.91	$478.83
Balance, (in dollars per share)	$335.83	$383.05	$335.83	$0
Aggregate Intrinsic Value	106,386	109,914	106,386	0
Weighted Average Remaining Contractual Term	6 years 11 months	6 years 6 months		0 days
Vested and exercisable
Number of Shares		88,118
Weighted Average Exercise Price (in dollars per share)		$306.32
Aggregate Intrinsic Value		73,481
Weighted Average Remaining Contractual Term		5 years 8 months
Vested and exercisable and expected to vest thereafter, net of estimated forfeitures
Number of Shares		144,077
Weighted Average Exercise Price (in dollars per share)		$382.81
Aggregate Intrinsic Value		$109,124
Weighted Average Remaining Contractual Term		6 years 6 months

INVESTMENTS_Details

INVESTMENTS (Details) (USD $)	1 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Short-term Investments
Investments
Cost		$1,142,881	$5,462,613
Gross Unrealized Gains		39	483
Gross Unrealized Losses		-738	-376
Fair Value		1,142,182	5,462,720
Short-term Investments \| Foreign government securities
Investments
Cost		52,524	4,019,530
Gross Unrealized Gains		0	233
Gross Unrealized Losses		-34	-356
Fair Value		52,490	4,019,407
Short-term Investments \| U.S. government securities
Investments
Cost		364,276	1,443,083
Gross Unrealized Gains		24	250
Gross Unrealized Losses		-34	-20
Fair Value		364,266	1,443,313
Short-term Investments \| U.S. commercial paper
Investments
Cost		621,252
Gross Unrealized Gains		15
Gross Unrealized Losses		-652
Fair Value		620,615
Short-term Investments \| U.S. government agency securities
Investments
Cost		104,829
Gross Unrealized Gains		0
Gross Unrealized Losses		-18
Fair Value		104,811
Long-term Investments
Investments
Cost		3,920,019
Gross Unrealized Gains		2,476
Gross Unrealized Losses		-166,842
Fair Value		3,755,653
Long-term Investments \| Foreign government securities
Investments
Cost		12,707
Gross Unrealized Gains		0
Gross Unrealized Losses		-36
Fair Value		12,671
Long-term Investments \| U.S. government securities
Investments
Cost		557,130
Gross Unrealized Gains		80
Gross Unrealized Losses		-762
Fair Value		556,448
Long-term Investments \| U.S. corporate debt securities
Investments
Cost		2,332,030
Gross Unrealized Gains		2,299
Gross Unrealized Losses		-5,296
Fair Value		2,329,033
Long-term Investments \| U.S. government agency securities
Investments
Cost		95,108
Gross Unrealized Gains		97
Gross Unrealized Losses		-111
Fair Value		95,094
Long-term Investments \| U.S. municipal securities
Investments
Cost		1,114
Gross Unrealized Gains		0
Gross Unrealized Losses		-12
Fair Value		1,102
Ctrip.com International, Ltd.
Investments
Debt Investment, Term	5 years
Period over which Ctrip ADSs can be acquired	12 months
Maximum Ownership Percentage in Ctrip	10.00%
Ctrip.com International, Ltd. \| Long-term Investments \| Ctrip corporate debt securities
Investments
Cost	500,000	500,000
Gross Unrealized Gains		0
Gross Unrealized Losses		-74,039
Fair Value		425,961
Ctrip.com International, Ltd. \| Long-term Investments \| Ctrip equity securities
Investments
Cost		421,930
Gross Unrealized Gains		0
Gross Unrealized Losses		-86,586
Fair Value		$335,344

FAIR_VALUE_MEASUREMENTS_Detail

FAIR VALUE MEASUREMENTS (Details) (Recurring Basis, USD $)	Dec. 31, 2014	Dec. 31, 2013
ASSETS:
Total assets at fair value	$7,143,021,000	$6,163,064,000
Level 1
ASSETS:
Total assets at fair value	490,952,000	433,850,000
Level 2
ASSETS:
Total assets at fair value	6,652,069,000	5,729,214,000
Cash equivalents \| Money market funds
ASSETS:
Total assets at fair value	155,608,000	433,850,000
Cash equivalents \| Foreign government securities
ASSETS:
Total assets at fair value	974,855,000	238,202,000
Cash equivalents \| U.S. government securities
ASSETS:
Total assets at fair value	676,503,000	28,000,000
Cash equivalents \| U.S. commercial paper
ASSETS:
Total assets at fair value	427,884,000
Cash equivalents \| U.S. government agency securities
ASSETS:
Total assets at fair value	10,000,000
Cash equivalents \| Level 1 \| Money market funds
ASSETS:
Total assets at fair value	155,608,000	433,850,000
Cash equivalents \| Level 1 \| Foreign government securities
ASSETS:
Total assets at fair value	0	0
Cash equivalents \| Level 1 \| U.S. government securities
ASSETS:
Total assets at fair value	0	0
Cash equivalents \| Level 1 \| U.S. commercial paper
ASSETS:
Total assets at fair value	0
Cash equivalents \| Level 1 \| U.S. government agency securities
ASSETS:
Total assets at fair value	0
Cash equivalents \| Level 2 \| Money market funds
ASSETS:
Total assets at fair value	0	0
Cash equivalents \| Level 2 \| Foreign government securities
ASSETS:
Total assets at fair value	974,855,000	238,202,000
Cash equivalents \| Level 2 \| U.S. government securities
ASSETS:
Total assets at fair value	676,503,000	28,000,000
Cash equivalents \| Level 2 \| U.S. commercial paper
ASSETS:
Total assets at fair value	427,884,000
Cash equivalents \| Level 2 \| U.S. government agency securities
ASSETS:
Total assets at fair value	10,000,000
Short-term Investments \| Foreign government securities
ASSETS:
Total assets at fair value	52,490,000	4,019,407,000
Short-term Investments \| U.S. government securities
ASSETS:
Total assets at fair value	364,266,000	1,443,313,000
Short-term Investments \| U.S. commercial paper
ASSETS:
Total assets at fair value	620,615,000
Short-term Investments \| U.S. government agency securities
ASSETS:
Total assets at fair value	104,811,000
Short-term Investments \| Level 1 \| Foreign government securities
ASSETS:
Total assets at fair value	0	0
Short-term Investments \| Level 1 \| U.S. government securities
ASSETS:
Total assets at fair value	0	0
Short-term Investments \| Level 1 \| U.S. commercial paper
ASSETS:
Total assets at fair value	0
Short-term Investments \| Level 1 \| U.S. government agency securities
ASSETS:
Total assets at fair value	0
Short-term Investments \| Level 2 \| Foreign government securities
ASSETS:
Total assets at fair value	52,490,000	4,019,407,000
Short-term Investments \| Level 2 \| U.S. government securities
ASSETS:
Total assets at fair value	364,266,000	1,443,313,000
Short-term Investments \| Level 2 \| U.S. commercial paper
ASSETS:
Total assets at fair value	620,615,000
Short-term Investments \| Level 2 \| U.S. government agency securities
ASSETS:
Total assets at fair value	104,811,000
Long-term Investments \| Foreign government securities
ASSETS:
Total assets at fair value	12,671,000
Long-term Investments \| U.S. government securities
ASSETS:
Total assets at fair value	556,448,000
Long-term Investments \| U.S. government agency securities
ASSETS:
Total assets at fair value	95,094,000
Long-term Investments \| U.S. municipal securities
ASSETS:
Total assets at fair value	1,102,000
Long-term Investments \| U.S. corporate debt securities
ASSETS:
Total assets at fair value	2,329,033,000
Long-term Investments \| Ctrip corporate debt securities
ASSETS:
Total assets at fair value	425,961,000
Long-term Investments \| Ctrip equity securities
ASSETS:
Total assets at fair value	335,344,000
Long-term Investments \| Level 1 \| Foreign government securities
ASSETS:
Total assets at fair value	0
Long-term Investments \| Level 1 \| U.S. government securities
ASSETS:
Total assets at fair value	0
Long-term Investments \| Level 1 \| U.S. government agency securities
ASSETS:
Total assets at fair value	0
Long-term Investments \| Level 1 \| U.S. municipal securities
ASSETS:
Total assets at fair value	0
Long-term Investments \| Level 1 \| U.S. corporate debt securities
ASSETS:
Total assets at fair value	0
Long-term Investments \| Level 1 \| Ctrip corporate debt securities
ASSETS:
Total assets at fair value	0
Long-term Investments \| Level 1 \| Ctrip equity securities
ASSETS:
Total assets at fair value	335,344,000
Long-term Investments \| Level 2 \| Foreign government securities
ASSETS:
Total assets at fair value	12,671,000
Long-term Investments \| Level 2 \| U.S. government securities
ASSETS:
Total assets at fair value	556,448,000
Long-term Investments \| Level 2 \| U.S. government agency securities
ASSETS:
Total assets at fair value	95,094,000
Long-term Investments \| Level 2 \| U.S. municipal securities
ASSETS:
Total assets at fair value	1,102,000
Long-term Investments \| Level 2 \| U.S. corporate debt securities
ASSETS:
Total assets at fair value	2,329,033,000
Long-term Investments \| Level 2 \| Ctrip corporate debt securities
ASSETS:
Total assets at fair value	425,961,000
Long-term Investments \| Level 2 \| Ctrip equity securities
ASSETS:
Total assets at fair value	0
Foreign exchange derivatives
LIABILITIES:
Total liabilities at fair value	129,000	122,091,000
Foreign exchange derivatives \| Level 1
LIABILITIES:
Total liabilities at fair value	0	0
Foreign exchange derivatives \| Level 2
LIABILITIES:
Total liabilities at fair value	129,000	122,091,000
Foreign exchange derivatives \| Short-term Investments
ASSETS:
Total assets at fair value	336,000	292,000
Foreign exchange derivatives \| Short-term Investments \| Level 1
ASSETS:
Total assets at fair value	0	0
Foreign exchange derivatives \| Short-term Investments \| Level 2
ASSETS:
Total assets at fair value	$336,000	$292,000

FAIR_VALUE_MEASUREMENTS_Narrat

FAIR VALUE MEASUREMENTS (Narrative) (Details)

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2013

USD ($)

Foreign Currency Contracts

Foreign Exchange Contracts, Translation Risk

Foreign Exchange Contracts, Transaction Risk

Net Investment Hedging

USD ($)

Foreign Currency Contracts

USD ($)

EUR (€)

Derivatives Not Designated as Hedging Instruments

Foreign exchange gains (losses) recorded in "Foreign currency transactions and other"

$13,700,000

$300,000

$700,000

($21,800,000)

$3,600,000

$800,000

Foreign Currency Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net

200,000

-500,000

Foreign exchange derivative assets recorded in "Prepaid expenses and other current assets"

300,000

100,000

Foreign exchange derivative liabilities recorded in "Accrued expenses and other current liabilities"

100,000

600,000

Foreign exchange gains (losses), net of derivative activity

-11,800,000

-5,500,000

Payments for Derivative Instrument Operating Activities

8,900,000

Proceeds for Derivative Instrument Operating Activities

4,400,000

1,900,000

Derivatives Designated as Hedging Instruments

Derivative, Notional Amount

3,000,000,000

Fair value of derivatives, net

-121,300,000

Derivative liabilities recorded in "Accrued expense and other current liabilities"

121,500,000

Derivative assets recorded in "Prepaid expenses and other current assets"

200,000

Payments for Hedge, Investing Activities

94,661,000

81,870,000

4,014,000

80,300,000

78,600,000

Proceeds from foreign currency contracts

$14,354,000

$3,266,000

$86,159,000

$82,100,000

ACCOUNTS_RECEIVABLE_RESERVES_D

ACCOUNTS RECEIVABLE RESERVES (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Receivables [Abstract]
Balance, beginning of year	$14,116	$10,322	$6,103
Provision charged to expense	22,990	16,451	16,094
Charge-offs and adjustments	-21,546	-13,072	-11,977
Currency translation adjustments	-1,348	415	102
Balance, end of year	$14,212	$14,116	$10,322

NET_INCOME_PER_SHARE_Details

NET INCOME PER SHARE (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 23, 2013	Dec. 31, 2006
Anti-dilutive Securities Excluded From Computation Of Earnings Per Share
Weighted average number of basic common shares outstanding	52,301,000	50,924,000	49,840,000
Weighted average dilutive stock options, restricted stock units and performance share units	340,000	382,000	501,000
Assumed conversion of Convertible Senior Notes	382,000	1,107,000	985,000
Weighted average number of diluted common and common equivalent shares outstanding	53,023,000	52,413,000	51,326,000
Option indexed to issuer's equity, settlement alternatives, shares, at Fair Value				42,160
Convertible Debt 0.75 Percent Due September 2013
Anti-dilutive Securities Excluded From Computation Of Earnings Per Share
Debt Instrument, Face Amount					$172.50
Outstanding Stock Awards
Anti-dilutive Securities Excluded From Computation Of Earnings Per Share
Anti-dilutive potential common shares	2,574,000	2,384,000	2,202,000
Convertible Debt
Anti-dilutive Securities Excluded From Computation Of Earnings Per Share
Anti-dilutive potential common shares	2,100,000	2,000,000	2,000,000

PROPERTY_AND_EQUIPMENT_Details

PROPERTY AND EQUIPMENT (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$442,947	$312,787
Less: accumulated depreciation and amortization	-243,994	-177,734
Property and equipment, net	198,953	135,053
Depreciation	78,241	48,365	32,818
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	332,650	244,845
Computer equipment and software \| Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	2 years
Computer equipment and software \| Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	5 years
Office equipment, furniture, fixtures & leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$110,297	$67,942
Office equipment, furniture, fixtures & leasehold improvements \| Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	2 years
Office equipment, furniture, fixtures & leasehold improvements \| Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	11 years

INTANGIBLE_ASSETS_AND_GOODWILL2

INTANGIBLE ASSETS AND GOODWILL (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Finite-lived intangible assets
Gross Carrying Amount	$2,690,263	$1,270,870
Accumulated Amortization	-355,502	-250,885
Net Carrying Amount	2,334,761	1,019,985	208,113
Intangible assets amortization expense	129,579	69,610	32,323
Annual estimated amortization expense for intangible assets
2015	171,007
2016	167,887
2017	160,296
2018	141,776
2019	131,727
Thereafter	1,562,068
Total	2,334,761
Goodwill
Balance, beginning of year	1,767,912	522,672
Acquisitions	1,590,829	1,232,342
Currency translation adjustments	-32,267	12,898
Balance, end of year	3,326,474	1,767,912	522,672
Supply and distribution agreements
Finite-lived intangible assets
Gross Carrying Amount	842,642	581,742
Accumulated Amortization	-188,441	-160,499
Net Carrying Amount	654,201	421,243
Weighted Average Useful Life	16 years
Supply and distribution agreements \| Minimum
Finite-lived intangible assets
Amortization Period	10 years
Supply and distribution agreements \| Maximum
Finite-lived intangible assets
Amortization Period	20 years
Technology
Finite-lived intangible assets
Gross Carrying Amount	108,987	93,322
Accumulated Amortization	-43,746	-29,271
Net Carrying Amount	65,241	64,051
Weighted Average Useful Life	5 years
Technology \| Minimum
Finite-lived intangible assets
Amortization Period	1 year
Technology \| Maximum
Finite-lived intangible assets
Amortization Period	5 years
Patents
Finite-lived intangible assets
Gross Carrying Amount	1,623	1,623
Accumulated Amortization	-1,524	-1,478
Net Carrying Amount	99	145
Amortization Period	15 years
Weighted Average Useful Life	15 years
Internet domain names
Finite-lived intangible assets
Gross Carrying Amount	41,652	45,799
Accumulated Amortization	-16,895	-12,112
Net Carrying Amount	24,757	33,687
Weighted Average Useful Life	8 years
Internet domain names \| Minimum
Finite-lived intangible assets
Amortization Period	2 years
Internet domain names \| Maximum
Finite-lived intangible assets
Amortization Period	20 years
Trade names
Finite-lived intangible assets
Gross Carrying Amount	1,674,218	548,243
Accumulated Amortization	-100,850	-47,388
Net Carrying Amount	1,573,368	500,855
Weighted Average Useful Life	20 years
Trade names \| Minimum
Finite-lived intangible assets
Amortization Period	5 years
Trade names \| Maximum
Finite-lived intangible assets
Amortization Period	20 years
Non-compete agreements
Finite-lived intangible assets
Gross Carrying Amount	21,000	0
Accumulated Amortization	-3,908	0
Net Carrying Amount	17,092	0
Amortization Period	3 years
Weighted Average Useful Life	3 years
Other
Finite-lived intangible assets
Gross Carrying Amount	141	141
Accumulated Amortization	-138	-137
Net Carrying Amount	$3	$4
Weighted Average Useful Life	3 years
Other \| Minimum
Finite-lived intangible assets
Amortization Period	3 years
Other \| Maximum
Finite-lived intangible assets
Amortization Period	10 years

OTHER_ASSETS_Details

OTHER ASSETS (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Investments, All Other Investments [Abstract]
Deferred debt issuance costs	$27,204	$16,465
Security deposits	12,368	10,617
Deferred tax assets	8,548	7,055
Other	9,228	6,432
Total	$57,348	$40,569

OTHER_ASSETS_Narrative_Details

OTHER ASSETS (Narrative) (Details)

Dec. 31, 2014

Dec. 31, 2013

Mar. 31, 2012

Dec. 31, 2014

Dec. 31, 2013

Mar. 31, 2010

Dec. 31, 2014

Dec. 31, 2013

31-May-13

Dec. 31, 2014

Aug. 31, 2014

Dec. 31, 2014

Sep. 30, 2014

Dec. 31, 2014

Dec. 31, 2013

Oct. 31, 2011

In Millions, unless otherwise specified

1.00% Convertible Senior Notes Due March 2018

1.25% Convertible Senior Notes Due March 2015

0.35% Senior Convertible Notes Due June 2020

0.9% Senior Convertible Notes Due September 2021

2.375% Senior Notes Due September 2024

Convertible Debt Converted Debt

Revolving credit facility

USD ($)

EUR (€)

USD ($)

Debt Instrument

Debt Instrument, Face Amount

$1,000

$575

$1,000

€ 1,000

$1,000

Interest rate stated percentage (as a percent)

1.00%

1.25%

0.35%

0.90%

2.38%

Write off of Deferred Debt Issuance Cost

$0.50

$2.40

DEBT_Narrative_Details

DEBT (Narrative) (Details)

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Mar. 31, 2010

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2010

Mar. 31, 2010

Mar. 31, 2012

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2013

Mar. 31, 2012

31-May-13

Dec. 31, 2014

Dec. 31, 2013

Jun. 30, 2013

31-May-13

Aug. 31, 2014

Dec. 31, 2014

Aug. 31, 2014

Dec. 31, 2014

Sep. 30, 2014

Oct. 31, 2011

Dec. 31, 2014

Dec. 31, 2013

Oct. 31, 2011

Jul. 24, 2014

Oct. 31, 2011

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

USD ($)

Convertible Notes

Convertible Debt 1.25 Percent Due March 2015

1.00% Convertible Senior Notes Due March 2018

0.35% Senior Convertible Notes Due June 2020

0.9% Senior Convertible Notes Due September 2021

2.375% Senior Notes Due September 2024

Revolving Credit Facility

Letter of Credit

Swingline Loans

OpenTable

London Interbank Offered Rate (LIBOR)

Federal Funds Purchased

One Month LIBOR

Convertible Debt 1.25 Percent Due March 2015

Convertible Debt Converted Debt

USD ($)

Minimum

Maximum

USD ($)

Minimum

Maximum

USD ($)

Minimum

Maximum

USD ($)

Minimum

Maximum

USD ($)

EUR (€)

USD ($)

Minimum

Maximum

Rate 2C

USD ($)

Revolving Credit Facility

USD ($)

Minimum

Maximum

USD ($)

Rate 1

Rate 2B

Rate 2C

Minimum

Maximum

Debt Instrument

Revolving credit facility

$1,000,000,000

$100,000,000

$50,000,000

Period of revolving credit facility (in years)

5 years

Debt Instrument, Basis Spread on Variable Rate

0.00%

0.50%

1.00%

1.50%

0.50%

1.00%

Line of Credit Facility, Unused Capacity, Commitment Fee Percentage

0.10%

0.25%

Carrying Value

3,849,756,000

1,742,047,000

925,166,000

903,203,000

861,886,000

838,844,000

863,701,000

1,199,003,000

995,000,000

Letters of Credit Outstanding, Amount

4,000,000

2,200,000

Interest rate stated percentage (as a percent)

1.25%

1.00%

0.35%

0.90%

2.38%

Reclassification Adjustment for Convertible Debt in Mezzanine

300,000

8,500,000

Estimated market value of outstanding senior notes

4,800,000,000

3,100,000,000

Cash repayment of principal amount of convertible debt

122,900,000

414,600,000

Shares issued in satisfaction of conversion value in excess of principal amount (in shares)

300,256

972,235

Cash paid in satisfaction of conversion value in excess of principal amount

2,200,000

Debt Instrument, Face Amount

575,000,000

1,000,000,000

Unamortized Debt Discount

360,312,000

257,953,000

329,000

8,533,000

74,834,000

96,797,000

20,000,000

138,114,000

161,156,000

136,299,000

11,065,000

9,400,000

Debt financing costs paid

13,300,000

20,900,000

1,000,000

11,000,000

6,500,000

Debt Instrument, Convertible, Conversion Price

$303.06

$944.61

$1,315.10

$2,055.50

Debt Instrument, Convertible, Threshold Consecutive Trading Days

20 days

30 days

20 days

30 days

20 days

30 days

20 days

30 days

Ratio of closing share price to conversion price as a condition for conversion of convertible 2015 Senior Notes, minimum (as a percent)

150.00%

Additional Payment To Debt Holder Settled In Shares Aggregate Value Of Shares

344,000,000

397,000,000

375,000,000

Effective interest rate at debt origination or modification (as a percent)

5.89%

3.50%

3.13%

3.18%

Debt discount related to convertible notes, net of tax

69,100,000

80,900,000

92,400,000

82,500,000

Debt discount related to convertible notes, before tax

115,200,000

135,200,000

154,300,000

142,900,000

Finance costs related to convertible notes, net of tax

1,600,000

2,800,000

100,000

1,600,000

Interest expense related to Senior Notes

75,300,000

78,200,000

59,400,000

8,600,000

Contractual coupon interest related to convertible notes included in interest expense

17,100,000

17,700,000

15,200,000

Amortization of debt discount included in interest expense

54,731,000

55,718,000

39,820,000

54,400,000

55,700,000

39,800,000

2,600,000

1,500,000

Amortization of debt issuance costs included in interest expense

3,800,000

4,800,000

4,400,000

Unamortized debt issuance costs written off to interest expense related to debt conversions

500,000

2,400,000

Debt Instrument, Interest Rate During Period

3.50%

4.50%

4.80%

2.50%

Losses on extinguishment of debt, pretax

-6,270,000

-26,661,000

6,300,000

26,700,000

Losses on extinguishment of debt, net of tax

$3,800,000

$16,200,000

DEBT_Details

DEBT (Details)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2010	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	31-May-13	Dec. 31, 2014	Aug. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Sep. 30, 2014
	USD ($)	USD ($)	1.25% Convertible Senior Notes Due March 2015	1.25% Convertible Senior Notes Due March 2015	1.25% Convertible Senior Notes Due March 2015	1.00% Convertible Senior Notes Due March 2018	1.00% Convertible Senior Notes Due March 2018	1.00% Convertible Senior Notes Due March 2018	0.35% Senior Convertible Notes Due June 2020	0.35% Senior Convertible Notes Due June 2020	0.35% Senior Convertible Notes Due June 2020	0.9% Senior Convertible Notes Due September 2021	0.9% Senior Convertible Notes Due September 2021	2.375% Senior Notes Due September 2024	2.375% Senior Notes Due September 2024	2.375% Senior Notes Due September 2024
			USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	EUR (€)	EUR (€)
Debt Instrument
Interest rate stated percentage (as a percent)			1.25%	1.25%	1.25%	1.00%	1.00%	1.00%	0.35%	0.35%	0.35%	0.90%	0.90%	2.38%	2.38%	2.38%
Debt Instrument, Face Amount					$575,000,000			$1,000,000,000			$1,000,000,000		$1,000,000,000		€ 1,000,000,000	€ 1,000,000,000
Outstanding Principal Amount	4,210,068,000	2,000,000,000	37,524,000	160,464,000		1,000,000,000	1,000,000,000		1,000,000,000	1,000,000,000		1,000,000,000		1,210,068,000
Unamortized Debt Discount	-360,312,000	-257,953,000	-329,000	-8,533,000		-74,834,000	-96,797,000		-138,114,000	-161,156,000	-20,000,000	-136,299,000		-11,065,000		-9,400,000
Carrying Value, Short Term			37,195,000	151,931,000
Carrying Value, Long Term	$3,849,756,000	$1,742,047,000				$925,166,000	$903,203,000		$861,886,000	$838,844,000		$863,701,000		$1,199,003,000

TREASURY_STOCK_Details

TREASURY STOCK (Details) (USD $)	1 Months Ended	3 Months Ended					12 Months Ended
TREASURY STOCK (Details) (USD $)	Oct. 31, 2013	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 05, 2015
Subsequent Event [Line Items]
Stock repurchase program, authorized amount					$1,000,000,000
Repurchase of common stock, excluding repurchase of common shares to satisfy employee withholding tax obligations related to stock-based compensation (in shares)		438,897	114,645	484,361	431,910	263,913
Repurchase of common stock, excluding repurchase of common shares to satisfy employee withholding tax obligations related to stock-based compensation		500,000,000	147,300,000	459,200,000	345,500,000	166,200,000
Remaining authorization of repurchase common stock		7,200,000					7,200,000
Reacquired shares, settlement of conversion spread hedges (in shares)	42,160
Reacquired shares, settlement of conversion spread hedges, value	43,100,000							19,000
Repurchase of common shares to satisfy employee withholding tax obligations related to stock-based compensation (in shares)							77,761	113,503	141,229
Repurchase of common shares to satisfy employee withholding tax obligations related to stock-based compensation							103,100,000	78,800,000	90,800,000
Treasury stock, shares		9,888,024					9,888,024	9,256,721
Subsequent Event
Subsequent Event [Line Items]
Stock repurchase program, authorized amount										$3,000,000,000

REDEEMABLE_NONCONTROLLING_INTE2

REDEEMABLE NONCONTROLLING INTERESTS (Details) (USD $)	1 Months Ended			12 Months Ended						0 Months Ended	1 Months Ended
REDEEMABLE NONCONTROLLING INTERESTS (Details) (USD $)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011	18-May-10	Jun. 30, 2010	Mar. 31, 2011
Redeemable noncontrolling interest
Proportion of redeemable shares subject to put and call options in each of 2011, 2012 and 2013					0.33		0.33		0.33
Payments for Repurchase of Redeemable Noncontrolling Interest	$192,500,000	$61,100,000	$13,000,000	$0	$192,530,000		$61,079,000
Reconciliation of redeemable noncontrolling interests
Fair value adjustments				0	-42,522,000		-84,693,000
Priceline.com International Limited (PIL)
Redeemable noncontrolling interest
Payments to purchase a controlling interest of the outstanding equity of TravelJigsaw Holdings Limited and its operating subsidiary										108,500,000
Noncontrolling Interest, Ownership Percentage by Parent		12.70%	19.00%									24.40%
Reconciliation of redeemable noncontrolling interests
Balance, beginning of period					160,287,000		127,045,000
Net income attributable to noncontrolling interests					135,000		4,471,000
Fair value adjustments					42,522,000	[1]	84,693,000	[1]
Purchase of subsidiary shares at fair value					-192,530,000	[1]	-61,079,000	[1]
Currency translation adjustments					-10,414,000		5,157,000
Balance, end of period					$0		$160,287,000
Bookingcom Limited [Member]
Redeemable noncontrolling interest
Percent purchased, by certain key members of the management team of Booking.com, of ownership interest in TravelJigsaw from PIL (as a percent)											3.00%

[1]	The fair value of the redeemable noncontrolling interests was determined by industry peer comparable analysis and a discounted cash flow valuation model.

ACCUMULATED_OTHER_COMPREHENSIV2

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustments, net of tax	($102,758,000)	[1]	$84,598,000	[1]
Net unrealized gain (loss) on investment securities, net of tax	-157,144,000	[2]	131,000	[2]
Accumulated other comprehensive income (loss)	-259,902,000		84,729,000
Net unrealized gain (loss) on investment securities, before tax	-164,700,000		200,000
2.375% Senior Notes Due September 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net gain (loss) from fair value adjustments associated with net investment hedges, before tax	83,800,000
Non-Derivative used in Net Investment Hedge, Net of Tax	48,300,000
Foreign Exchange Forward
Accumulated Other Comprehensive Income (Loss) [Line Items]
Derivatives used in Net Investment Hedge, Net of Tax	-37,800,000		-58,700,000
Net gain (loss) from fair value adjustments associated with net investment hedges, before tax	($57,800,000)		($98,800,000)

[1]	Foreign currency translation adjustments, net of tax, includes net losses from fair value adjustments at DecemberB 31, 2014 of $37.8 million after tax ($57.8 million before tax) and a net losses from fair value adjustments at DecemberB 31, 2013 of $58.7 million after tax ($98.8 million before tax) associated with derivatives designated as net investment hedges (see Note 5).Foreign currency translation adjustments, net of tax, includes foreign currency transaction gains at DecemberB 31, 2014 of $48.3 million after tax ($83.8 million before tax) associated with the Company's 2024 Notes, which are Euro denominated debt, designated as a net investment hedge (see Note 11). The remaining balance in currency translation adjustments excludes income taxes as a result of the Company's intention to indefinitely reinvest the earnings of its non-U.S. subsidiaries outside of the United States.
[2]	The unrealized loss before tax at DecemberB 31, 2014 was $164.7 million compared to an unrealized gain before tax at DecemberB 31, 2013 of $0.2 million.

INCOME_TAXES_Narrative_Details

INCOME TAXES (Narrative) (Details) (USD $)	12 Months Ended
INCOME TAXES (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
International pre-tax income	$2,900,000,000	$2,200,000,000	$1,700,000,000
Domestic pre-tax income	98,400,000	48,500,000	95,000,000
Deferred tax assets	8,548,000	7,055,000
Current deferred tax liabilities	1,200,000	38,000
Less valuation allowance on deferred tax assets	-161,997,000	-173,558,000
Valuation allowance related to federal and state net operating loss carryforwards derived from equity transactions	140,400,000
Valuation allowance related to international operations	21,600,000
Federal tax deductions related to equity transactions not included in deferred tax assets	250,000,000
International earnings for which no U.S. tax provision has been made	7,300,000,000
Effective income tax rate on qualifying innovative activities at Innovation Box Tax rate (as a percent)	5.00%
Statutory federal rate (as a percent)	35.00%
Federal
Operating Loss Carryforwards [Line Items]
Maximum change in ownership percentage allowed before statutory limitations imposed on the availability of net operating losses (as a percent)	50.00%
Estimated aggregate limitation of cumulative net operating losses available net of limit imposed by IRC Section 382	1,200,000,000
Federal \| Operating loss
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	22,000,000
Federal \| Equity-related
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	1,200,000,000
State \| Operating loss
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	673,400,000
Foreign
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	131,200,000
Foreign \| Operating loss
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	49,300,000
Foreign \| Capital allowance
Operating Loss Carryforwards [Line Items]
Other tax carryforwards	1,700,000
Canada \| Operating loss
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	3,700,000
Domestic \| Research credit
Operating Loss Carryforwards [Line Items]
Other tax carryforwards	$29,600,000
Dutch
Operating Loss Carryforwards [Line Items]
Statutory federal rate (as a percent)	25.00%

INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current
International	$496,719	$396,162	$302,352
U.S. Federal	10,316	5,250	3,681
U.S. State	28,953	13,431	12,203
Total	535,988	414,843	318,236
Deferred
International	-10,613	-16,314	-13,792
U.S. Federal	47,847	11,454	37,956
U.S. State	-5,527	-6,244	-4,568
Total	31,707	-11,104	19,596
Total
International	486,106	379,848	288,560
U.S. Federal	58,163	16,704	41,637
U.S. State	23,426	7,187	7,635
Income tax expense	$567,695	$403,739	$337,832

INCOME_TAXES_Deferred_Tax_Asse

INCOME TAXES (Deferred Tax Assets/(Liabilities)) (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Deferred tax assets/(liabilities).
Net operating loss carryforward b U.S.	$176,786		$263,994
Net operating loss carryforward b International	22,353		21,660
Fixed assets	0		818
Accrued expenses	41,117		22,708
Stock-based compensation and other stock based payments	54,935		40,346
Other	24,456		33,530
Subtotal	319,647		383,056
Discount on convertible notes	-141,193		-97,550
Intangible assets and other	-856,807		-356,669
Euro denominated debt	-35,441		0
Fixed assets	-3,409		0
Less valuation allowance on deferred tax assets	-161,997		-173,558
Net deferred tax assets (liabilities)	($879,200)	[1]	($244,721)	[1]

[1]	Includes non-current deferred tax assets of $8.5 million and $7.1 million as of DecemberB 31, 2014 and 2013, respectively, reported in "Other assets" on the Consolidated Balance Sheets and current deferred tax liabilities of $1.2 million and $38 thousand as of DecemberB 31, 2014 and 2013, respectively, reported in "Accrued expenses and other current liabilities" on the Consolidated Balance Sheets.

INCOME_TAXES_Effective_Income_

INCOME TAXES (Effective Income Tax Rate Reconciliation and Income Tax Contingencies) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of effective income tax rate and amount computed using expected U.S. statutory federal rate
Income tax expense at federal statutory rate	$1,046,307	$803,788	$616,654
Adjustment due to:
Foreign rate differential	-289,692	-226,894	-175,932
Innovation Box Tax benefit	-233,545	-177,195	-118,916
Other	44,625	4,040	16,026
Income tax expense	567,695	403,739	337,832
Unrecognized tax benefits
Unrecognized tax benefit b January 1	22,104	7,343	3,192
Gross increases b tax positions in current period	9,305	8,597	4,423
Gross increases b tax positions in prior periods	6,569	3,507	343
Increase acquired in business combination	17,767	7,089	0
Gross decreases b tax positions in prior periods	-2,164	-495	-615
Reduction due to lapse in statute of limitations	-346	-3,937	0
Reduction due to settlements during the current period	-879	0	0
Unrecognized tax benefit b December 31	$52,356	$22,104	$7,343

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES (Narrative) (Details) (USD $)	12 Months Ended	0 Months Ended	1 Months Ended		3 Months Ended		1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Aug. 20, 2012	Jan. 31, 2013	Jul. 31, 2009	Mar. 31, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
	Dec. 31, 2014	complaint	Jan. 31, 2013	Jul. 31, 2009	Mar. 31, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Employment Contracts [Abstract]
Maximum cash severance payments provided for in the employment agreements	$26
Extension period for health and insurance benefits after termination, high end of range (in years)	3 years
Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Approximate number of lawsuits brought by or against states, cities and counties over issues involving the payment of hotel occupancy and other taxes	40
Litigation Related to Anti-trust Violations
Loss Contingency Complaints Filed Alleging Antitrust Violations [Abstract]
Loss Contingency Complaint Filed Alleging Antitrust Violations		1
Loss Continency Other Complaints Alleging Antitrust Violations		31
US Merchant Hotel Business \| Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Reserve for the potential resolution of issues related to travel transaction taxes (in dollars)	52							55
City of San Francisco \| Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Assessed taxes including interest and penalties (in dollars)			2.7	3.4
COLORADO \| Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Minimum number of municipalities and counties which have initiated audit proceedings	1
Number of appeals remaining unresolved	15
UTAH \| Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Audit notices and administrative procedures, number of cities	5
District of Columbia \| Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Assessed taxes including interest and penalties (in dollars)					5.6	4.8
HAWAII \| Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Assessed taxes including interest and penalties (in dollars)					18.7		16.5
Payments of tax and interest for loss contingency related to travel transaction taxes (in dollars)	2.2							20.6
Minimum \| Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Minimum number of municipalities and counties which have initiated audit proceedings	79
Minimum number of states which have initiated audit proceedings	11
Minimum \| State of California \| Litigation Related to Hotel Occupany and Other Taxes
Travel Transaction Taxes
Minimum number of municipalities and counties which have initiated audit proceedings	40
Norwalk, Connecticut \| Priceline.com Incorporated
Real Estate [Abstract]
Area of Real Estate Property	70,000
Amsterdam, Netherlands \| Bookingcom BV
Real Estate [Abstract]
Area of Real Estate Property	202,000
Bangkok, Thailand \| Mauritius Company Limited (formerly known as Agoda)
Real Estate [Abstract]
Area of Real Estate Property	118,000
Stamford, Connecticut \| KAYAK
Real Estate [Abstract]
Area of Real Estate Property	18,000
San Francisco, California \| OpenTable
Real Estate [Abstract]
Area of Real Estate Property	51,000
Manchester, England \| Rentalcars.com
Real Estate [Abstract]
Area of Real Estate Property	63,000
Office Leases [Member]
Real Estate [Abstract]
Rental expense	57.2							40	30.9
Data Center Space, Leases [Member]
Real Estate [Abstract]
Rental expense	$15							$13	$11

COMMITMENTS_AND_CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Details) (USD $)	12 Months Ended
COMMITMENTS AND CONTINGENCIES (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Minimum payments for operating leases having initial or remaining non-cancelable lease terms
2015	$79,902,000
2016	73,853,000
2017	59,583,000
2018	50,239,000
2019	42,918,000
After 2019	130,891,000
Total	437,386,000
Office Leases [Member]
Minimum payments for operating leases having initial or remaining non-cancelable lease terms
Rental expense	57,200,000	40,000,000	30,900,000
Data Center Space, Leases [Member]
Minimum payments for operating leases having initial or remaining non-cancelable lease terms
Rental expense	$15,000,000	$13,000,000	$11,000,000

BENEFIT_PLANS_Details

BENEFIT PLANS (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Defined Contribution Plan, Cost Recognized	$6.20	$5.80	$5

GEOGRAPHIC_INFORMATION_Details

GEOGRAPHIC INFORMATION (Details) (USD $)	3 Months Ended																12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Geographic Information
Revenues	$1,840,097	[1]	$2,836,497	[1]	$2,123,575	[1]	$1,641,802	[1]	$1,541,153	[1]	$2,269,903	[1]	$1,680,238	[1]	$1,302,012	[1]	$8,441,971	$6,793,306	$5,260,956
Intangible assets, net	2,334,761								1,019,985								2,334,761	1,019,985	208,113
Goodwill	3,326,474								1,767,912								3,326,474	1,767,912	522,672
Other long-lived assets	255,639								175,622								255,639	175,622	156,582
United States
Geographic Information
Revenues																	1,798,484	1,769,696	1,661,710
Intangible assets, net	2,183,957								838,494								2,183,957	838,494	1,337
Goodwill	2,712,479								1,247,686								2,712,479	1,247,686	37,306
Other long-lived assets	80,668								49,750								80,668	49,750	76,623
The Netherlands
Geographic Information
Revenues																	5,519,207	4,103,393	2,675,976
Intangible assets, net	108,650								123,847								108,650	123,847	137,255
Goodwill	224,731								156,261								224,731	156,261	149,464
Other long-lived assets	97,056								61,164								97,056	61,164	37,035
Other
Geographic Information
Revenues																	1,124,280	920,217	923,270
Intangible assets, net	42,154								57,644								42,154	57,644	69,521
Goodwill	389,264								363,965								389,264	363,965	335,902
Other long-lived assets	$77,915								$64,708								$77,915	$64,708	$42,924

[1]	As the Company's retail accommodation business, which recognizes revenue at the completion of the stay, continues to expand, our quarterly results become increasingly impacted by seasonal factors.

SELECTED_QUARTERLY_FINANCIAL_D2

SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $)	3 Months Ended																12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$1,840,097	[1]	$2,836,497	[1]	$2,123,575	[1]	$1,641,802	[1]	$1,541,153	[1]	$2,269,903	[1]	$1,680,238	[1]	$1,302,012	[1]	$8,441,971	$6,793,306	$5,260,956
Gross profit	1,674,685		2,619,978		1,882,996		1,406,471		1,333,301		1,989,065		1,383,855		1,009,665		7,584,130	5,715,886	4,083,681
Net income	451,831		1,062,253		576,451		331,218		378,077		832,989		437,440		244,292		2,421,753	1,892,798	1,424,037
Net income applicable to common stockholders	$451,831		$1,062,253		$576,451		$331,218		$378,077		$832,989		$437,326		$244,271		$2,421,753	$1,892,663	$1,419,566
Net income applicable to common stockholders per basic common share	$8.65		$20.27		$11		$6.35		$7.32		$16.22		$8.62		$4.89		$46.30	$37.17	$28.48
Net income applicable to common stockholders per diluted common share	$8.56		$20.03		$10.89		$6.25		$7.14		$15.72		$8.39		$4.76		$45.67	$36.11	$27.66

[1]	As the Company's retail accommodation business, which recognizes revenue at the completion of the stay, continues to expand, our quarterly results become increasingly impacted by seasonal factors.

ACQUISITIONS_Details

ACQUISITIONS (Details) (USD $)	12 Months Ended				0 Months Ended	3 Months Ended	0 Months Ended
ACQUISITIONS (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Jul. 24, 2014	Jun. 30, 2014	21-May-13	21-May-13
Business Acquisition [Line Items]
Acquisition related costs	$6,900,000
Goodwill	3,326,474,000		1,767,912,000	522,672,000
Stock issuance costs paid	0		1,191,000	0
OpenTable
Business Acquisition [Line Items]
Purchase price, total consideration	2,529,000,000				2,500,000,000
Purchase price net of cash acquired					2,400,000,000
Business Acquisition, Share Price					$103
Acquisition date fair value of assumed equity awards					95,000,000
Number of Restaurants					32,000
Cash Acquired from Acquisition	126,000,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	18 years 10 months
Current assets	203,000,000	[1]
Identifiable intangible assets	1,435,000,000	[2]
Deferred Tax Liabilities, Intangible Assets	543,000,000
Goodwill	1,500,000,000	[3]
Other long-term assets	38,000,000
Total liabilities	-647,000,000	[4]
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired						98,000,000
Business Combination, Contingent Consideration, Liability	10,700,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low	0
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	71,000,000
KAYAK
Business Acquisition [Line Items]
Purchase price, total consideration							2,100,000,000	2,100,000,000
Purchase price net of cash acquired							1,900,000,000	1,900,000,000
Acquisition date fair value of assumed equity awards							57,400,000
Acquisition related costs			8,500,000
Business Acquisition, Percentage of Voting Interests Acquired							100.00%	100.00%
Payments to Acquire Businesses, Gross								500,000,000
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable								1,600,000,000
Stock issuance costs paid			1,200,000
Trade names \| OpenTable
Business Acquisition [Line Items]
Identifiable intangible assets	1,100,000,000
Amortization Period	20 years
Customer Relationships \| OpenTable
Business Acquisition [Line Items]
Identifiable intangible assets	290,000,000
Amortization Period	15 years
Technology-Based Intangible Assets \| OpenTable
Business Acquisition [Line Items]
Identifiable intangible assets	$15,000,000
Amortization Period	5 years

[1]	Includes cash acquired of $126 million.
[2]	Acquired definite-lived intangibles, with a weighted average life of 18.8 years, consisted of trade names of $1.1 billion with an estimated useful life of 20 years, supply and distribution agreements of $290 million with an estimated useful life of 15 years, and technology of $15 million with estimated useful life of 5 years.
[3]	Goodwill is not tax deductible.
[4]	Includes deferred tax liabilities of $543 million.