Altaba (AABA) 10-Q 12 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'YHOO	'
Entity Registrant Name	'YAHOO INC	'
Entity Central Index Key	'0001011006	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	1,014,442,318

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$842,428	$2,667,778
Short-term marketable securities	987,870	1,516,175
Accounts receivable, net	844,118	1,008,448
Prepaid expenses and other current assets	891,807	460,312
Total current assets	3,566,223	5,652,713
Long-term marketable securities	1,384,638	1,838,425
Property and equipment, net	1,536,362	1,685,845
Goodwill	4,704,859	3,826,749
Intangible assets, net	427,351	153,973
Other long-term assets	165,866	289,130
Investments in equity interests	3,120,450	2,840,157
Total assets	14,905,749	17,103,253
Current liabilities:	'	'
Accounts payable	123,042	184,831
Accrued expenses and other current liabilities	776,466	808,475
Deferred revenue	293,615	296,926
Total current liabilities	1,193,123	1,290,232
Long-term deferred revenue	295,970	407,560
Capital lease and other long-term liabilities	121,169	124,587
Deferred and other long-term tax liabilities, net	749,168	675,271
Total liabilities	2,359,430	2,497,650
Commitments and contingencies (Note 11)	'	'
Yahoo! Inc. stockholders' equity:	'	'
Common stock, $0.001 par value; 5,000,000 shares authorized; 1,189,816 shares issued and 1,115,233 shares outstanding as of December 31, 2012 and 1,210,154 shares issued and 1,013,059 shares outstanding as of September 30, 2013	1,205	1,187
Additional paid-in capital	9,902,748	9,563,348
Treasury stock at cost, 74,583 shares as of December 31, 2012 and 197,095 shares as of September 30, 2013	-4,481,162	-1,368,043
Retained earnings	6,810,550	5,792,459
Accumulated other comprehensive income	260,770	571,249
Total Yahoo! Inc. stockholders' equity	12,494,111	14,560,200
Noncontrolling interests	52,208	45,403
Total equity	12,546,319	14,605,603
Total liabilities and equity	14,905,749	17,103,253
Redeemable Preferred Stock	'	'
Current assets:	'	'
Alibaba Group Preference Shares	'	$816,261

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Per Share data, unless otherwise specified
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	5,000,000	5,000,000
Common stock, shares issued	1,210,154	1,189,816
Common stock, shares outstanding	1,013,059	1,115,233
Treasury stock at cost, shares	197,095	74,583

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue	$1,138,973	$1,201,732	$3,414,585	$3,640,759
Operating expenses:	'	'	'	'
Cost of revenue - traffic acquisition costs	58,464	112,829	188,848	393,945
Cost of revenue - other	271,763	282,081	821,032	814,513
Sales and marketing	282,562	269,272	819,319	827,450
Product development	267,444	217,301	723,272	645,407
General and administrative	151,304	135,249	419,764	395,637
Amortization of intangibles	15,253	8,084	30,702	27,893
Restructuring charges (reversals), net	-576	24,727	-4,060	159,536
Total operating expenses	1,046,214	1,049,543	2,998,877	3,264,381
Income from operations	92,759	152,189	415,708	376,378
Other income, net	5,370	4,607,656	46,048	4,630,109
Income before income taxes and earnings in equity interests	98,129	4,759,845	461,756	5,006,487
Provision for income taxes	-31,891	-1,774,094	-111,894	-1,857,036
Earnings in equity interests	232,756	175,265	675,034	527,499
Net income	298,994	3,161,016	1,024,896	3,676,950
Net income attributable to noncontrolling interests	-2,338	-778	-6,805	-3,738
Net income attributable to Yahoo! Inc.	296,656	3,160,238	1,018,091	3,673,212
Net income attributable to Yahoo! Inc. common stockholders per share - basic	$0.29	$2.66	$0.96	$3.05
Net income attributable to Yahoo! Inc. common stockholders per share - diluted	$0.28	$2.64	$0.93	$3.02
Shares used in per share calculation - basic	1,024,289	1,186,046	1,065,949	1,205,050
Shares used in per share calculation - diluted	1,041,698	1,195,085	1,081,495	1,214,430
Stock-based compensation expense by function:	'	'	'	'
Stock-based compensation expense	80,726	61,366	193,467	166,903
Restructuring expense reversals	'	'	'	-3,429
Cost of revenue - other	'	'	'	'
Stock-based compensation expense by function:	'	'	'	'
Stock-based compensation expense	2,608	2,363	9,215	7,871
Sales and marketing	'	'	'	'
Stock-based compensation expense by function:	'	'	'	'
Stock-based compensation expense	29,175	19,876	68,995	59,954
Product development	'	'	'	'
Stock-based compensation expense by function:	'	'	'	'
Stock-based compensation expense	28,702	17,050	57,502	54,329
General and administrative	'	'	'	'
Stock-based compensation expense by function:	'	'	'	'
Stock-based compensation expense	$20,241	$22,077	$57,755	$44,749

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Comprehensive income	'	'	'	'
Net income	$298,994	$3,161,016	$1,024,896	$3,676,950
Available-for-sale securities:	'	'	'	'
Unrealized gains (losses) on available-for-sale securities, net of taxes of $(246) and $(2,390) for the three months ended September 30, 2012 and 2013, respectively, and $(41) and $598 for the nine months ended September 30, 2012 and 2013, respectively	-2,072	463	2,046	6,143
Reclassification adjustment for realized (gains) losses on available-for-sale securities included in net income, net of taxes of $57 and $187 for the three months ended September 30, 2012 and 2013, respectively, and $(5,298) and $390 for the nine months ended September 30, 2012 and 2013, respectively	-312	-98	-651	9,260
Net change in unrealized gains (losses) on available-for-sale securities, net of tax	-2,384	365	1,395	15,403
Foreign currency translation adjustments ("CTA"):	'	'	'	'
Foreign CTA gains (losses), net of tax	-41,838	28,009	-567,197	-193,128
Net investment hedge CTA gains (losses), net of tax	-15,165	'	254,572	'
Net foreign CTA gains (losses), net of tax	-57,003	28,009	-312,625	-193,128
Cash flow hedges:	'	'	'	'
Unrealized gains (losses) on cash flow hedges, net of taxes of nil and $249 for the three months ended September 30, 2012 and 2013, respectively, and nil and $(114) for the nine months ended September 30, 2012 and 2013, respectively	856	'	867	'
Reclassification adjustment for realized (gains) losses on cash flow hedges, net of taxes of nil and $(65) for the three months ended September 30, 2012 and 2013, respectively, and nil and $69 for the nine months ended September 30, 2012 and 2013, respectively	-106	'	-83	'
Net change in unrealized gains (losses) on cash flow hedges, net of tax	750	'	784	'
Other comprehensive income (loss)	-58,637	28,374	-310,446	-177,725
Comprehensive income	240,357	3,189,390	714,450	3,499,225
Less: comprehensive income attributable to noncontrolling interests	-2,338	-778	-6,805	-3,738
Comprehensive income attributable to Yahoo! Inc.	$238,019	$3,188,612	$707,645	$3,495,487

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Unrealized gains (losses) on available-for-sale securities, taxes	($2,390)	($246)	$598	($41)
Reclassification adjustment for realized (gains) losses on available-for-sale securities included in net income, taxes	187	57	390	-5,298
Unrealized gains (losses) on cash flow hedges, taxes	249	'	-114	'
Reclassification adjustment for realized (gains) losses on cash flow hedges, taxes	($65)	'	$69	'

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	$1,024,896	$3,676,950
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation	412,646	401,022
Amortization of intangible assets	68,365	84,087
Stock-based compensation expense, net	193,467	163,474
Non-cash restructuring charges	547	40,462
Dividend income related to Alibaba Group Preference Shares	-35,726	'
Dividends received from equity investees	135,058	83,648
Tax benefits (detriments) from stock-based awards	33,894	-9,471
Excess tax benefits from stock-based awards	-47,193	-30,751
Deferred income taxes	-74,981	-891,288
Earnings in equity interests	-675,034	-527,499
Gain from sale of Alibaba Group Shares	'	-4,603,322
(Gain) loss from sales of investments, assets, and other, net	19,994	-18,308
Changes in assets and liabilities, net of effects of acquisitions:	'	'
Accounts receivable, net	161,459	86,942
Prepaid expenses and other	-17,738	41,059
Accounts payable	-54,343	-22,457
Accrued expenses and other liabilities	-183,706	2,628,962
Deferred revenue	-114,085	514,811
Net cash provided by operating activities	847,520	1,618,321
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Acquisition of property and equipment, net	-229,310	-355,787
Purchases of marketable securities	-2,247,302	-1,838,860
Proceeds from sales of marketable securities	2,642,548	684,979
Proceeds from maturities of marketable securities	557,565	250,653
Proceeds related to sale of Alibaba Group Shares, net	'	6,247,728
Proceeds related to the redemption of Alibaba Group Preference Shares	800,000	'
Proceeds from the sale of investments	'	26,132
Acquisitions, net of cash acquired	-1,187,229	'
Purchases of intangible assets	-2,290	-3,088
Other investing activities, net	-11,045	-9,421
Net cash provided by investing activities	322,937	5,002,336
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Proceeds from issuance of common stock	203,417	116,420
Repurchases of common stock	-3,113,118	-716,379
Excess tax benefits from stock-based awards	47,193	30,751
Tax withholdings related to net share settlements of restricted stock units	-106,177	-48,097
Proceeds from credit facility borrowings	150,000	'
Repayment of credit facility borrowings	-150,150	'
Other financing activities	-5,713	-3,519
Net cash used in financing activities	-2,974,548	-620,824
Effect of exchange rate changes on cash and cash equivalents	-21,259	-1,823
Net change in cash and cash equivalents	-1,825,350	5,998,010
Cash and cash equivalents at beginning of period	2,667,778	1,562,390
Cash and cash equivalents at end of period	$842,428	$7,560,400

THE_COMPANY_AND_SUMMARY_OF_SIG

THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2013
THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
	Note 1 THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	The Company. Yahoo! Inc., together with its consolidated subsidiaries (“Yahoo” or the “Company”), is focused on making the world’s daily habits inspiring and entertaining. By creating highly personalized experiences for its users, the Company keeps people connected to what matters most to them, across devices and around the world. The Company creates value for advertisers by connecting them with the audiences that build their businesses. Advertisers can build their businesses through advertising to targeted audiences on the Company’s online properties and services (“Yahoo Properties”), or through a distribution network of third-party entities (“Affiliates”) who integrate the Company’s advertising offerings into their Websites or other offerings (those Websites and other offerings, “Affiliate sites”).
	Basis of Presentation. The condensed consolidated financial statements include the accounts of Yahoo! Inc. and its majority-owned or otherwise controlled subsidiaries. All significant intercompany accounts and transactions have been eliminated. Investments in entities in which the Company can exercise significant influence, but does not own a majority equity interest or otherwise control, are accounted for using the equity method and are included as investments in equity interests on the condensed consolidated balance sheets. The Company has included the results of operations of acquired companies from the date of the acquisition.
	The accompanying unaudited condensed consolidated interim financial statements reflect all adjustments, consisting of only normal recurring items, which, in the opinion of management, are necessary for a fair statement of the results of operations for the periods shown. The results of operations for such periods are not necessarily indicative of the results expected for the full year or for any future periods.
	The preparation of consolidated financial statements in conformity with generally accepted accounting principles (“GAAP”) in the United States (“U.S.”) requires management to make estimates, judgments, and assumptions that affect the reported amounts of assets, liabilities, revenue, and expenses and the related disclosure of contingent assets and liabilities. On an ongoing basis, the Company evaluates its estimates, including those related to revenue, the useful lives of long-lived assets including property and equipment and intangible assets, investment fair values, stock-based compensation, goodwill, income taxes, contingencies, and restructuring charges. The Company bases its estimates of the carrying value of certain assets and liabilities on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, when these carrying values are not readily available from other sources. Actual results may differ from these estimates.
	These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The condensed consolidated balance sheet as of December 31, 2012 was derived from the Company’s audited financial statements for the year ended December 31, 2012, but does not include all disclosures required by U.S. GAAP. However, the Company believes the disclosures are adequate to make the information presented not misleading.

INVESTMENTS_AND_FAIR_VALUE_MEA

INVESTMENTS AND FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2013
INVESTMENTS AND FAIR VALUE MEASUREMENTS	'
	Note 2 INVESTMENTS AND FAIR VALUE MEASUREMENTS
	The following tables summarize the investments in available-for-sale securities (in thousands):
			December 31, 2012
			Gross		Gross			Gross			Estimated
			Amortized		Unrealized			Unrealized			Fair Value
			Costs		Gains			Losses
	Government and agency securities		$	1,312,876	$	985		$	(45	)	$	1,313,816
	Corporate debt securities, commercial paper, and bank certificates of deposit			2,039,809		1,597			(622	)		2,040,784
	Corporate equity securities			230		—			(33	)		197
	Alibaba Group Preference Shares			816,261		—			—			816,261
	Total investments in available-for-sale securities		$	4,169,176	$	2,582		$	(700	)	$	4,171,058
			September 30, 2013
			Gross		Gross			Gross			Estimated
			Amortized		Unrealized			Unrealized			Fair Value
			Costs		Gains			Losses
	Government and agency securities		$	294,644	$	110		$	(180	)	$	294,574
	Corporate debt securities, commercial paper, and bank certificates of deposit			2,078,519		1,339			(1,924	)		2,077,934
	Corporate equity and other marketable securities			230		141			—			371
	Total investments in available-for-sale securities		$	2,373,393	$	1,590		$	(2,104	)	$	2,372,879
			December 31,		September 30,
			2012		2013
	Reported as:
	Short-term marketable securities		$	1,516,175	$	987,870
	Long-term marketable securities			1,838,425		1,384,638
	Alibaba Group Preference Shares			816,261		—
	Other assets			197		371
	Total		$	4,171,058	$	2,372,879
	Available-for-sale securities included in cash and cash equivalents on the condensed consolidated balance sheets are not included in the table above as the gross unrealized gains and losses were not material as of December 31, 2012 and September 30, 2013 as the carrying value approximates fair value because of the short maturity of those instruments. Realized gains and losses from sales of marketable securities were not material for the three and nine months ended September 30, 2012 and 2013.
	The contractual maturities of available-for-sale marketable securities were as follows (in thousands):
			December 31,		September 30,
			2012		2013
	Due within one year		$	1,516,175	$	987,870
	Due after one year through five years			1,838,425		1,384,638
	Total available-for-sale marketable securities		$	3,354,600	$	2,372,508
	The following tables show all investments in an unrealized loss position for which an other-than-temporary impairment has not been recognized and the related gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):
			December 31, 2012
			Less than 12 Months					12 Months or Greater						Total
			Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
			Value		Loss			Value			Loss			Value		Loss
	Government and agency securities		$	165,025	$	(45	)	$	—		$	—		$	165,025	$	(45	)
	Corporate debt securities, commercial paper, and bank certificates of deposit			729,046		(622	)		—			—			729,046		(622	)
	Corporate equity securities			197		(33	)		—			—			197		(33	)
	Total investments in available-for-sale securities		$	894,268	$	(700	)	$	—		$	—		$	894,268	$	(700	)
			September 30, 2013
			Less than 12 Months					12 Months or Greater						Total
			Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
			Value		Loss			Value			Loss			Value		Loss
	Government and agency securities		$	110,362	$	(180	)	$	—		$	—		$	110,362	$	(180	)
	Corporate debt securities, commercial paper, and bank certificates of deposit			948,913		(1,924	)		—			—			948,913		(1,924	)
	Total investments in available-for-sale securities		$	1,059,275	$	(2,104	)	$	—		$	—		$	1,059,275	$	(2,104	)
	The Company’s investment portfolio consists of liquid high-quality fixed income government, agency, and corporate debt securities, money market funds, and time deposits with financial institutions. Investments in fixed rate instruments carry a degree of interest rate risk. Fixed rate securities may have their fair value adversely impacted due to a rise in interest rates or by a deterioration of the credit quality of the issuer. The longer the term of the securities, the more susceptible they are to changes in market rates. Investments are reviewed periodically to identify possible other-than-temporary impairment. The Company has no current requirement or intent to sell the securities in an unrealized loss position. The Company expects to recover up to (or beyond) the initial cost of investment for securities held.
	The Company’s investment in the Alibaba Group Preference Shares was presented as an asset carried at estimated fair value on the Company’s condensed consolidated balance sheet as of December 31, 2012. As of December 31, 2012, the carrying value of the Alibaba Group Preference Shares approximated the fair value. As of December 31, 2012, the total fair value of the Alibaba Group Preferences Shares was $822 million, which included $6 million of accrued dividend income recorded within prepaid expenses and other current assets and $16 million of accrued dividend income recorded as part of the carrying value of the Alibaba Group Preference Shares. On May 16, 2013, Alibaba Group Holding Limited (“Alibaba Group”) exercised its right to redeem the Alibaba Group Preference Shares for $846 million in cash. The cash received represented the redemption value, which included the stated value of $800 million plus accrued dividends of $46 million.
	The following table sets forth the financial assets and liabilities, measured at fair value, by level within the fair value hierarchy as of December 31, 2012 (in thousands):
			Fair Value Measurements at Reporting Date Using
	Assets		Level 1		Level 2			Level 3			Total
	Money market funds(1)		$	685,707	$	—		$	—		$	685,707
	Available-for-sale securities:
	Government and agency securities(1)			—		2,464,227			—			2,464,227
	Commercial paper and bank certificates of deposit(1)			—		892,769			—			892,769
	Corporate debt securities(1)			—		1,298,123			—			1,298,123
	Time deposits			—		84,555			—			84,555
	Alibaba Group Preference Shares			—		—			816,261			816,261
	Corporate equity securities(2)			197		—			—			197
Foreign currency derivative contracts(3)			—		5,007			—			5,007
Financial assets at fair value		$	685,904	$	4,744,681		$	816,261		$	6,246,846
Liabilities
Foreign currency derivative contracts(3)			—		(6,662	)		—			(6,662	)
Total financial assets and liabilities at fair value		$	685,904	$	4,738,019		$	816,261		$	6,240,184
The following table sets forth the financial assets and liabilities, measured at fair value, by level within the fair value hierarchy as of September 30, 2013 (in thousands):
		Fair Value Measurements at Reporting Date Using
Assets		Level 1		Level 2			Total
Money market funds(1)		$	76,782	$	—		$	76,782
Available-for-sale securities:
Government and agency securities(1)			—		322,377			322,377
Commercial paper and bank certificates of deposit(1)			—		291,886			291,886
Corporate debt securities(1)			—		1,786,048			1,786,048
Time deposits			—		80,261			80,261
Corporate equity and other marketable securities(2)			371		—			371
Foreign currency derivative contracts(3)			—		418,044			418,044
Financial assets at fair value		$	77,153	$	2,898,616		$	2,975,769
Liabilities
Foreign currency derivative contracts(3)			—		(10,865	)		(10,865	)
Total financial assets and liabilities at fair value		$	77,153	$	2,887,751		$	2,964,904
(1)	The money market funds, government and agency securities, commercial paper and bank certificates of deposit, and corporate debt securities are classified as part of either cash and cash equivalents or investments in marketable securities in the condensed consolidated balance sheets.
(2)	The corporate equity securities are classified as part of the other long-term assets and other marketable securities are classified as investments in marketable securities in the condensed consolidated balance sheets.
(3)	Foreign currency derivative contracts are classified as part of either other current assets or other current liabilities in the condensed consolidated balance sheets. The notional amounts of the foreign currency derivative contracts were $3.4 billion, including contracts designated as net investment hedges of $3 billion, as of December 31, 2012, and $2.9 billion, including contracts designated as net investment hedges of $2.5 billion, as of September 30, 2013.
The amount of cash and cash equivalents as of December 31, 2012 and September 30, 2013 included $597 million and $658 million, respectively, of cash deposits.
The fair values of the Company’s Level 1 financial assets and liabilities are based on quoted market prices of the identical underlying security. The fair values of the Company’s Level 2 financial assets and liabilities are obtained using quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets in markets that are not active; and inputs other than quoted prices, e.g., interest rates and yield curves. The Company utilizes a pricing service to assist in obtaining fair value pricing for the majority of the investment portfolio. The Company classified its investment in the Alibaba Group Preference Shares within Level 3 because it was valued using significant unobservable inputs. To estimate the fair value as of December 31, 2012, the Company performed benchmarking by comparing the terms and conditions of the Alibaba Group Preference Shares to dividend rates, subordination terms, and credit ratings of those of similar type instruments. The Company conducts reviews on a quarterly basis to verify pricing, assess liquidity, and determine if significant inputs have changed that would impact the fair value hierarchy disclosure.
Activity between Levels of the Fair Value Hierarchy. During the year ended December 31, 2012, the Company did not make any transfers between Level 1, Level 2, or Level 3 assets or liabilities. During the nine months ended September 30, 2013, the Company did not make any transfers between Level 1 and Level 2 assets or liabilities.

CONSOLIDATED_FINANCIAL_STATEME

CONSOLIDATED FINANCIAL STATEMENT DETAILS	9 Months Ended
	Sep. 30, 2013
CONSOLIDATED FINANCIAL STATEMENT DETAILS	'
	Note 3 CONSOLIDATED FINANCIAL STATEMENT DETAILS
	Accumulated Other Comprehensive Income
	The components of accumulated other comprehensive income were as follows (in thousands):
		December 31,			September 30,
		2012			2013
	Unrealized gains on available-for-sale securities, net of tax	$	9,121		$	11,267
	Foreign currency translation, net of tax		562,128			249,503
	Accumulated other comprehensive income	$	571,249		$	260,770
	Noncontrolling Interests
	Noncontrolling interests were as follows (in thousands):
		December 31,			September 30,
		2012			2013
	Beginning noncontrolling interests	$	40,280		$	45,403
	Net income attributable to noncontrolling interests		5,123			6,805
	Ending noncontrolling interests	$	45,403		$	52,208
	Other Income, Net
	Other income, net was as follows (in thousands):
		Three Months Ended					Nine Months Ended
		September 30,			September 30,		September 30,		September 30,
		2012			2013		2012		2013
	Interest, dividend, and investment income	$	6,402		$	5,362	$	15,682	$	53,214
	Gain related to sale of Alibaba Group Shares		4,603,322			—		4,603,322		—
	Other		(2,068	)		8		11,105		(7,166	)
	Total other income, net	$	4,607,656		$	5,370	$	4,630,109	$	46,048
	Interest, dividend and investment income consists of income earned from cash in bank accounts, investments made in marketable securities and money market funds, and dividend income on the Alibaba Group Preference Shares.
	The Company recorded a pre-tax gain of approximately $4.6 billion in the three and nine months ended September 30, 2012 related to the sale of Alibaba Group ordinary shares. See Note 8—“Investments in Equity Interests” for additional information.
	Other consists of gains and losses from sales or impairments of marketable securities and/or investments in privately-held companies, foreign exchange gains and losses due to re-measurement of monetary assets and liabilities denominated in non-functional currencies, foreign exchange gains and losses on balance sheet hedges, and other non-operating items.
	Reclassifications Out of Accumulated Other Comprehensive Income
	Reclassifications out of accumulated other comprehensive income for the three months ended September 30, 2013 were as follows (in thousands):
		Amount			Affected Line Item in the
		Reclassified from			Statement of Income
		Accumulated
		Other
		Comprehensive
		Income
	Realized gains on cash flow hedges, net of tax	$	(106	)		Revenue
	Realized gains on available-for-sale securities, net of tax		(312	)		Other income, net
	Total reclassifications for the period	$	(418	)
	Reclassifications out of accumulated other comprehensive income for the nine months ended September 30, 2013 were as follows (in thousands):
		Amount			Affected Line Item in the
		Reclassified from			Statement of Income
		Accumulated
		Other
		Comprehensive
		Income
	Realized gains on cash flow hedges, net of tax	$	(83	)		Revenue
	Realized gains on available-for-sale securities, net of tax		(651	)		Other income, net
	Total reclassifications for the period	$	(734	)

ACQUISITIONS

ACQUISITIONS	9 Months Ended
	Sep. 30, 2013
ACQUISITIONS	'
	Note 4 ACQUISITIONS
	Transactions completed in 2013
	Tumblr. On June 19, 2013, the Company completed the acquisition of Tumblr, Inc. (“Tumblr”), a blog-hosting website that allows users to post their own content as well as follow or re-blog posts made by other users. The acquisition of Tumblr brings a community of new users to the Yahoo network.
	The purchase price exceeded the fair value of the net tangible and identifiable intangible assets acquired from Tumblr and, as a result, the Company recorded goodwill in connection with this transaction. Under the terms of the agreement, the Company acquired all of the equity interests (including all outstanding vested options) in Tumblr. Tumblr stockholders and vested optionholders were paid in cash, outstanding Tumblr unvested options and restricted stock units were assumed and converted into equivalent awards covering Yahoo common stock and a portion of the Tumblr shares held by its founder were exchanged for Yahoo common stock.
	The total purchase price of approximately $990 million consisted mainly of cash consideration. The preliminary allocation of the purchase price of the assets acquired and liabilities assumed based on their fair values was as follows (in thousands):
	Cash and marketable securities acquired	$	16,587
	Other tangible assets acquired		73,780
	Amortizable intangible assets:
	Developed technology		23,700
	Customer contracts and related relationships		182,400
	Trade name		56,500
	Goodwill		751,114
	Total assets acquired		1,104,081
	Liabilities assumed		(113,870	)
	Total	$	990,211
	In connection with the acquisition, the Company is recognizing stock-based compensation expense of $70 million over a period of up to 4 years. This amount is comprised of assumed unvested stock options and restricted stock units (which had an aggregate fair value of $29 million at the acquisition date), and Yahoo common stock issued to Tumblr’s founder (which had a fair value of $41 million at the acquisition date). The Yahoo common stock issued to Tumblr’s founder is subject to holdback and will be released over four years provided he remains an employee of the Company. In addition, the transaction resulted in contingent cash consideration of $40 million to be paid to Tumblr’s founder over 4 years also provided that Tumblr’s founder remains an employee of the Company. Such cash payments are being recognized as compensation expense over the 4-year service period.
	The amortizable intangible assets have useful lives not exceeding 6 years and a weighted average useful life of 6 years. No amounts have been allocated to in-process research and development and $751 million has been allocated to goodwill. Goodwill represents the excess of the purchase price over the fair value of the net tangible and identifiable intangible assets acquired and is not deductible for tax purposes. This acquisition brings a community of new users to the Yahoo network by deploying Yahoo’s personalization technology and search infrastructure to deliver relevant content to the Tumblr user base. Operating results from the date of acquisition were not significant to the Company’s consolidated results of operations for the three and nine months ended September 30, 2013.
	Other Acquisitions — Business Combinations. During the nine months ended September 30, 2013, the Company acquired seventeen other companies, which were accounted for as business combinations. The total aggregate purchase price for these other acquisitions was $218 million. The total cash consideration of $218 million less cash acquired of $2 million resulted in a net cash outlay of $216 million. The preliminary allocation of the purchase price of the assets and liabilities assumed based on their estimated fair values was $77 million to amortizable intangible assets, $2 million to cash acquired, $23 million to other tangible assets, $32 million to assumed liabilities, and the remainder of $148 million to goodwill.
	The Company’s business combinations completed during the nine months ended September 30, 2013 did not have a material impact on the Company’s condensed consolidated financial statements, and therefore pro forma disclosures have not been presented.
	Transactions completed in 2012
	The Company did not make any acquisitions during the nine months ended September 30, 2012.

GOODWILL

GOODWILL	9 Months Ended
	Sep. 30, 2013
GOODWILL	'
	Note 5 GOODWILL
	The Company’s goodwill balance was $3.8 billion as of December 31, 2012, of which $2.9 billion was recorded in the Americas segment, $0.6 billion in the EMEA (Europe, Middle East and Africa) segment, and $0.3 billion in the Asia Pacific segment. As of September 30, 2013, the Company’s goodwill balance was $4.7 billion, of which $3.8 billion was recorded in the Americas segment, $0.6 billion in the EMEA segment, and $0.3 billion in the Asia Pacific segment. Goodwill related to the Tumblr acquisition, which was completed during June 2013, is included as part of the Americas segment. The increase in the carrying amount of goodwill of $878 million reflected on the Company’s condensed consolidated balance sheets during the nine months ended September 30, 2013 was primarily due to additions to goodwill of $899 million related to acquisitions made during the nine months ended September 30, 2013 offset by net foreign currency translation losses of $21 million.

INTANGIBLE_ASSETS_NET

INTANGIBLE ASSETS, NET	9 Months Ended
	Sep. 30, 2013
INTANGIBLE ASSETS, NET	'
	Note 6 INTANGIBLE ASSETS, NET
	The following table summarizes the Company’s intangible assets, net (in thousands):
			December 31, 2012		September 30, 2013
			Net		Gross Carrying		Accumulated			Net
					Amount		Amortization(*)
	Customer, affiliate, and advertiser related relationships		$	62,393	$	298,212	$	(80,605	)	$	217,607
	Developed technology and patents			71,634		269,920		(133,593	)		136,327
	Trade names, trademarks, and domain names			19,946		107,382		(33,965	)		73,417
	Total intangible assets, net		$	153,973	$	675,514	$	(248,163	)	$	427,351
	(*)	Cumulative foreign currency translation adjustments, reflecting movement in the currencies of the underlying entities increased total intangible assets by approximately $18 million as of September 30, 2013.
	For the three months ended September 30, 2012 and 2013, the Company recognized amortization expense for intangible assets of $24 million and $31 million, respectively, including $16 million in cost of revenue—other for both the three months ended September 30, 2012 and 2013. For the nine months ended September 30, 2012 and 2013, the Company recognized amortization expense for intangible assets of $84 million and $68 million, respectively, including $56 million and $38 million in cost of revenue—other for the nine months ended September 30, 2012 and 2013, respectively. Based on the current amount of intangibles subject to amortization, the estimated amortization expense for the remainder of 2013 and each of the succeeding years is as follows: three months ending December 31, 2013: $27 million; 2014: $101 million; 2015: $80 million; 2016: $55 million; and thereafter $148 million.

BASIC_AND_DILUTED_NET_INCOME_A

BASIC AND DILUTED NET INCOME ATTRIBUTABLE TO YAHOO! INC. COMMON STOCKHOLDERS PER SHARE	9 Months Ended
	Sep. 30, 2013
BASIC AND DILUTED NET INCOME ATTRIBUTABLE TO YAHOO! INC. COMMON STOCKHOLDERS PER SHARE	'
	Note 7 BASIC AND DILUTED NET INCOME ATTRIBUTABLE TO YAHOO! INC. COMMON STOCKHOLDERS PER SHARE
	Basic and diluted net income attributable to Yahoo common stockholders per share is computed using the weighted average number of common shares outstanding during the period, excluding net income attributable to participating securities (restricted stock units granted under the 1996 Directors’ Stock Plan (the “Directors’ Plan”)). Diluted net income per share is computed using the weighted average number of common shares and, if dilutive, potential common shares outstanding during the period. Potential common shares are calculated using the treasury stock method and consist of unvested restricted stock and shares underlying unvested restricted stock units, the incremental common shares issuable upon the exercise of stock options, and shares to be purchased under the 1996 Employee Stock Purchase Plan (the “Employee Stock Purchase Plan”). The Company calculates potential tax windfalls and shortfalls by including the impact of pro forma deferred tax assets.
	The Company takes into account the effect on consolidated net income per share of dilutive securities of entities in which the Company holds equity interests that are accounted for using the equity method.
	Potentially dilutive securities representing approximately 37 million and 44 million shares of common stock for the three and nine months ended September 30, 2012, respectively, and 4 million and 12 million shares of common stock for the three and nine months ended September 30, 2013, respectively, were excluded from the computation of diluted earnings per share for these periods because their effect would have been anti-dilutive.
	The following table sets forth the computation of basic and diluted net income per share (in thousands, except per share amounts):
		Three Months Ended						Nine Months Ended
		September 30,			September 30,			September 30,			September 30,
		2012			2013			2012			2013
	Basic:
	Numerator:
	Net income attributable to Yahoo! Inc.	$	3,160,238		$	296,656		$	3,673,212		$	1,018,091
	Less: Net income allocated to participating securities		(35	)		(6	)		(47	)		(24	)
	Net income attributable to Yahoo! Inc. common stockholders — basic	$	3,160,203		$	296,650		$	3,673,165		$	1,018,067
	Denominator:
	Weighted average common shares		1,186,046			1,024,289			1,205,050			1,065,949
	Net income attributable to Yahoo! Inc. common stockholders per share — basic	$	2.66		$	0.29		$	3.05		$	0.96
	Diluted:
	Numerator:
	Net income attributable to Yahoo! Inc.	$	3,160,238		$	296,656		$	3,673,212		$	1,018,091
	Less: Net income allocated to participating securities		(34	)		(6	)		(46	)		(24	)
	Less: Effect of dilutive securities issued by equity investees		(1,334	)		(5,040	)		(3,846	)		(10,778	)
	Net income attributable to Yahoo! Inc. common stockholders — diluted	$	3,158,870		$	291,610		$	3,669,320		$	1,007,289
	Denominator:
	Denominator for basic calculation		1,186,046			1,024,289			1,205,050			1,065,949
	Weighted average effect of Yahoo! Inc. dilutive securities:
	Restricted stock and restricted stock units		7,587			12,689			7,776			12,085
	Stock options and employee stock purchase plan		1,452			4,720			1,604			3,461
	Denominator for diluted calculation		1,195,085			1,041,698			1,214,430			1,081,495
	Net income attributable to Yahoo! Inc. common stockholders per share — diluted	$	2.64		$	0.28		$	3.02		$	0.93

INVESTMENTS_IN_EQUITY_INTEREST

INVESTMENTS IN EQUITY INTERESTS	9 Months Ended
	Sep. 30, 2013
INVESTMENTS IN EQUITY INTERESTS	'
	Note 8 INVESTMENTS IN EQUITY INTERESTS
	The following table summarizes the Company’s investments in equity interests (dollars in thousands):
		December 31,		Percent			September 30,		Percent
		2012		Ownership			2013		Ownership
	Alibaba Group	$	276,389		24	%	$	807,736		24	%
	Yahoo Japan		2,555,717		35	%		2,300,854		35	%
	Other		8,051		24	%		11,860		20	%
	Total	$	2,840,157				$	3,120,450
	Equity Investment in Alibaba Group. The investment in Alibaba Group is being accounted for using the equity method, and the total investment, including net tangible assets, identifiable intangible assets, and goodwill, is classified as part of the investments in equity interests balance on the Company’s condensed consolidated balance sheets. The Company’s accounting policy is to record its share of the results of Alibaba Group, and any related amortization expense and related tax impact, one quarter in arrears within earnings in equity interests in the condensed consolidated statements of income. As of September 30, 2013, the excess of carrying value of the Company’s investment in Alibaba Group and the Company’s proportionate share of the net assets of Alibaba Group is largely attributable to goodwill.
	Initial Repurchase by Alibaba Group. On September 18, 2012 (the “Repurchase Closing Date”), Alibaba Group repurchased 523 million of the 1,047 million ordinary shares of Alibaba Group (the “Shares”) owned by the Company (the “Initial Repurchase”). The Initial Repurchase was made pursuant to the terms of the Share Repurchase and Preference Share Sale Agreement entered into by Yahoo! Inc., Alibaba Group and Yahoo! Hong Kong Holdings Limited, a Hong Kong corporation and wholly-owned subsidiary of Yahoo! Inc. (“YHK”), on May 20, 2012 (as amended on September 11, 2012 and October 14, 2013, the “Repurchase Agreement”). Yahoo received $13.54 per Share, or approximately $7.1 billion in total consideration, for 523 million Shares sold to Alibaba Group. Approximately $6.3 billion of the consideration was received in cash and $800 million was received in Alibaba Group Preference Shares, which Alibaba Group redeemed on May 16, 2013. The Initial Repurchase resulted in a pre-tax gain of approximately $4.6 billion for the year ended December 31, 2012.
	The Alibaba Group Preference Shares yielded semi-annual dividends at a rate per annum of up to 10 percent, with at least 3 percent payable in cash and the remainder accruing and increasing the liquidation preference. The Alibaba Group Preference Shares were callable by Alibaba Group at the redemption value (including accrued dividends). On May 16, 2013, the Company received $846 million in cash from Alibaba Group to redeem the Alibaba Group Preference Shares. The cash received represented the redemption value, which included the stated value of $800 million plus accrued dividends of $46 million.
	The Repurchase Agreement provided that at the time Alibaba Group completes an initial public offering meeting certain specified criteria (a “Qualified IPO”), Yahoo and YHK would sell, at Alibaba Group’s election (either directly to Alibaba Group or in the Qualified IPO), up to 261.5 million of their remaining Shares. This amount was subsequently reduced to 208.0 million by an amendment to the Repurchase Agreement dated as of October 14, 2013. If Shares are sold back to Alibaba Group in the Qualified IPO, the purchase price per Share will be equal to the per share price in the Qualified IPO less specified fees and underwriter discounts. See Note 17 — “Subsequent Events” for additional information.
	On the Repurchase Closing Date, the Company and Alibaba Group entered into an amendment of their existing Technology and Intellectual Property License Agreement (the “TIPLA”) pursuant to which Alibaba Group made an initial payment to the Company of $550 million in satisfaction of certain future royalty payments under the existing TIPLA. The Company will recognize this revenue over the remaining four-year term of the TIPLA. For the three months ended September 30, 2012, the Company recognized approximately $5 million in revenue related to the initial payment. For the three and nine months ended September 30, 2013, the Company recognized approximately $34 million and $103 million, respectively, in revenue related to the initial payment. Alibaba Group will continue making royalty payments until the earlier of the fourth anniversary of the effective date of the amendment and a Qualified IPO. The Company recognized revenue relating to the continuing royalty payments under the TIPLA of approximately $19 million and $27 million for the three months ended September 30, 2012 and 2013, respectively, and approximately $51 million and $83 million for the nine months ended September 30, 2012 and 2013, respectively.
	The following table presents Alibaba Group’s U.S. GAAP financial information, as derived from the Alibaba Group financial statements (in thousands):
		Three Months Ended					Nine Months Ended
		June 30,		June 30,			June 30,		June 30,
		2012		2013			2012		2013
	Operating data:
	Revenue	$	1,077,045	$	1,737,180		$	2,905,752	$	4,959,274
	Gross profit	$	739,914	$	1,287,807		$	1,967,290	$	3,653,739
	Income from operations	$	371,854	$	855,791		$	861,775	$	2,317,273
	Net income	$	292,928	$	716,991		$	781,701	$	2,046,505
	Net income attributable to Alibaba Group	$	273,043	$	706,708		$	730,438	$	2,017,557
		September 30,		June 30,
		2012		2013
	Balance sheet data:
	Current assets	$	4,062,823	$	6,841,126
	Long-term assets	$	3,204,144	$	5,284,556
	Current liabilities	$	2,624,656	$	4,078,438
	Long-term liabilities	$	4,705,347	$	5,269,175
	Convertible preferred shares	$	1,317,526	$	1,695,269
	Noncontrolling interests	$	65,907	$	87,613
	Equity Investment in Yahoo Japan. The investment in Yahoo Japan Corporation (“Yahoo Japan”) is being accounted for using the equity method and the total investment, including net tangible assets, identifiable intangible assets, and goodwill, is classified as part of the investments in equity interests balance on the Company’s condensed consolidated balance sheets. The Company records its share of the results of Yahoo Japan, and any related amortization expense, one quarter in arrears within earnings in equity interests in the condensed consolidated statements of income.
	The Company makes adjustments to the earnings in equity interests line in the condensed consolidated statements of income for any differences between U.S. GAAP and accounting principles generally accepted in Japan (“Japanese GAAP”), the standards by which Yahoo Japan’s financial statements are prepared.
	The fair value of the Company’s ownership interest in the common stock of Yahoo Japan, based on the quoted stock price, was approximately $11.4 billion as of September 30, 2013.
	During the nine months ended September 30, 2012 and 2013, the Company received cash dividends from Yahoo Japan in the amount of $84 million and $77 million, net of withholding taxes, respectively, which were recorded as reductions to the Company’s investment in Yahoo Japan.
	The following tables present summarized financial information derived from Yahoo Japan’s consolidated financial statements, which are prepared on the basis of Japanese GAAP. The Company has made adjustments to the Yahoo Japan financial information to address differences between Japanese GAAP and U.S. GAAP that materially impact the summarized financial information below. Due to these adjustments, the Yahoo Japan summarized financial information presented below is not materially different than such information presented on the basis of U.S. GAAP.
		Three Months Ended					Nine Months Ended
		June 30,		June 30,			June 30,		June 30,
		2012		2013			2012		2013
		(in thousands)
	Operating data:
	Revenue	$	1,036,650	$	992,340		$	3,175,951	$	3,270,983
	Gross profit	$	877,116	$	818,441		$	2,693,956	$	2,733,506
	Income from operations	$	512,994	$	489,890		$	1,640,935	$	1,655,870
	Net income	$	315,949	$	364,612		$	966,646	$	1,056,323
	Net income attributable to Yahoo Japan	$	314,726	$	362,180		$	962,818	$	1,048,893
		September 30,		June 30,
		2012		2013
		(In thousands)
	Balance sheet data:
	Current assets	$	5,752,826	$	5,799,398
	Long-term assets	$	1,837,829	$	1,729,000
	Current liabilities	$	1,167,772	$	1,758,926
	Long-term liabilities	$	49,461	$	57,251
	Noncontrolling interests	$	31,034	$	58,247
	Under technology and trademark license and other commercial arrangements with Yahoo Japan, the Company records revenue from Yahoo Japan based on a percentage of advertising revenue earned by Yahoo Japan. The Company recorded revenue from Yahoo Japan of approximately $75 million and $65 million for the three months ended September 30, 2012 and 2013, respectively, and approximately $211 million and $199 million for the nine months ended September 30, 2012 and 2013, respectively. As of December 31, 2012 and September 30, 2013, the Company had net receivable balances from Yahoo Japan of approximately $43 million and $42 million, respectively.

DERIVATIVE_FINANCIAL_INSTRUMEN

DERIVATIVE FINANCIAL INSTRUMENTS	9 Months Ended
	Sep. 30, 2013
DERIVATIVE FINANCIAL INSTRUMENTS	'
	Note 9 DERIVATIVE FINANCIAL INSTRUMENTS
	The Company uses derivative financial instruments, primarily forward contracts, to mitigate risk associated with adverse movements in foreign currency exchange rates.
	The Company generally enters into master netting arrangements, which are designed to reduce credit risk by permitting net settlement of transactions with the same counterparty. The Company presents its derivative assets and liabilities at their gross fair values on the condensed consolidated balance sheets. The Company is not required to pledge, and is not entitled to receive, cash collateral related to these derivative transactions.
	Net Investment Hedges. In December 2012, the Company began hedging, on an after-tax basis, its net investment in Yahoo Japan with forward contracts to reduce the risk that its investment in Yahoo Japan will be adversely affected by foreign currency exchange rate fluctuations. At inception, the forward contracts had maturities ranging from 9 to 15 months. The Company applies hedge accounting on its forward contracts for the net investment hedge of Yahoo Japan. The total balance of the after-tax net investment hedge was less than the Yahoo Japan investment balance as of both December 31, 2012 and September 30, 2013. As such, the net investment hedge was considered to be effective, and, as a result, the changes in the fair value were recorded within accumulated other comprehensive income on the Company’s condensed consolidated balance sheets. The Company recognizes net investment derivative instruments as either an asset or a liability on the Company’s condensed consolidated balance sheets at fair value. The notional amounts of the foreign currency forward contracts were $3 billion and $2.5 billion as of December 31, 2012 and September 30, 2013, respectively. See Note 17 — “Subsequent Events” for additional information. The fair value of the foreign currency forward contract assets was $3 million as of December 31, 2012, and was included in prepaid expenses and other current assets on the Company’s condensed consolidated balance sheets. The fair values of the foreign currency forward contracts were a $416 million asset and a $4 million liability as of September 30, 2013, and were included in prepaid expenses and other current assets and accrued expenses and other current liabilities, respectively, on the Company’s condensed consolidated balance sheets. Pre-tax net gains of $3 million and $412 million were recorded as of December 31, 2012 and September 30, 2013, respectively, and were included in accumulated other comprehensive income on the Company’s condensed consolidated balance sheets.
	Cash Flow Hedges. In May 2013, the Company began hedging a portion of its forecasted revenue from Yahoo Japan with forward contracts to reduce the risk that its expected future cash flows from Yahoo Japan will be adversely affected by foreign currency exchange rate fluctuations. The Company entered into foreign currency forward contracts designated as cash flow hedges of varying maturities through January 31, 2014. For derivatives designated as cash flow hedges, the effective portion of the unrealized gains or losses on these forward contracts is recorded in accumulated other comprehensive income on the Company’s condensed consolidated balance sheets and reclassified into revenue on the condensed consolidated statements of income when the underlying hedged revenue is recognized. If the cash flow hedges were to become ineffective, the ineffective portion would be immediately recorded in other income, net on the Company’s condensed consolidated statements of income. The cash flow hedges were considered to be effective as of September 30, 2013. The total notional amount of the foreign currency forward contracts was $82 million as of September 30, 2013. The fair value of the foreign currency forward contracts was a less than $1 million net asset as of September 30, 2013; the contracts’ fair value was included in prepaid expenses and other current assets and accrued expenses and other current liabilities on the Company’s condensed consolidated balance sheets. A pre-tax net gain of less than $1 million was recorded as of September 30, 2013, which was included in accumulated other comprehensive income on the Company’s condensed consolidated balance sheets. For both the three and nine months ended September 30, 2013, the Company recorded gains of less than $1 million, net of tax, for cash flow hedges, which were recorded in revenue in the condensed consolidated statements of income. The Company expects all of the forward contracts designated as cash flow hedges to be reclassified to revenue within fiscal year 2013, as it expects to recognize the hedged anticipated revenue related to these contracts by December 31, 2013.
	Balance Sheet Hedges. The Company hedges its net recognized foreign currency assets and liabilities with foreign exchange forward contracts to reduce the risk that its earnings and cash flows will be adversely affected by changes in foreign currency exchange rates. These derivative instruments hedge assets and liabilities, including intercompany transactions, which are denominated in foreign currencies. The Company recognizes balance sheet derivative instruments as either assets or liabilities on the Company’s condensed consolidated balance sheets at fair value. Changes in the fair value of these derivatives are recorded in other income, net on the Company’s condensed consolidated statements of income. The notional amounts of the foreign currency forward contracts were $356 million and $398 million as of December 31, 2012 and September 30, 2013, respectively. As of December 31, 2012, the fair value of the foreign currency forward contracts was a $5 million liability which was included in accrued expenses and other current liabilities on the Company’s condensed consolidated balance sheet. As of September 30, 2013, the fair value of the foreign currency forward contracts was a $6 million net liability; the contracts’ fair value was included in prepaid expenses and other current assets and accrued expenses and other current liabilities on the Company’s condensed consolidated balance sheets. Gains of $13 million and losses of $11 million were recorded for the three months ended September 30, 2012 and 2013, respectively, and were included in other income, net on the Company’s condensed consolidated statements of income. Gains of $8 million and losses of $7 million were recorded for the nine months ended September 30, 2012 and 2013, respectively, and were included in other income, net on the Company’s condensed consolidated statements of income. The Company paid $6 million in cash for settlement of certain foreign currency forward contracts during the nine months ended September 30, 2013.
	Foreign currency forward contracts activity for the nine months ended September 30, 2013 was as follows (in millions):
			Beginning			Settlement		Gain (loss)			Gain (loss)			Gain		Ending fair
			fair value					recorded in			recorded in			(loss)		value
								other income,			other			recorded
								net			comprehensive			in
											income			revenue
	Derivatives designated as hedging instruments:
	Net investment hedges		$	3			—	$	—		$	409	(1)	$	—	$	412
	Cash flow hedges			—			—		—			1	(2)		—		1
	Derivatives not designated as hedging instruments:
	Balance sheet hedges			(5	)		6		(7	)		—			—		(6	)
	(1)	This amount does not reflect the tax impact of $154 million recorded during the nine months ended September 30, 2013. The $255 million after tax impact of the gain recorded under other comprehensive income was included in accumulated other comprehensive income on the Company’s condensed consolidated balance sheets.
	(2)	This amount does not reflect the tax impact of less than $1 million recorded during the nine months ended September 30, 2013. The less than $1 million after tax impact of the gain was included in accumulated other comprehensive income on the Company’s condensed consolidated balance sheets.

CREDIT_AGREEMENT

CREDIT AGREEMENT	9 Months Ended
	Sep. 30, 2013
CREDIT AGREEMENT	'
	Note 10 CREDIT AGREEMENT
	On October 19, 2012, the Company entered into a credit agreement (the “Credit Agreement”) with Citibank, N.A., as Administrative Agent, and the other lenders party thereto from time to time. The Credit Agreement provides for a $750 million unsecured revolving credit facility for a term maturing October 18, 2013 and subject to an extension for additional 364-day periods in accordance with the terms and conditions of the Credit Agreement. The Company may elect to increase the revolving credit facility by up to $250 million if existing or new lenders provide additional revolving commitments in accordance with the terms of the Credit Agreement. The proceeds from borrowings under the Credit Agreement, if any, are expected to be used for general corporate purposes. Borrowings under the Credit Agreement will bear interest at a rate equal to, at the Company’s option, either (a) a customary London interbank offered rate (a “Eurodollar Rate”), or (b) a customary base rate (a “Base Rate”), in each case plus an applicable margin. During the three and nine months ended September 30, 2013, the applicable margin for borrowings under the Credit Agreement was based upon the leverage ratio of the Company and ranged from 1.25 percent to 1.50 percent with respect to Eurodollar Rate borrowings and 0.25 percent to 0.50 percent with respect to Base Rate borrowings. See Note 17 — “Subsequent Events” for additional information.
	During the three months ended September 30, 2013, the Company borrowed $150 million under the Credit Agreement and subsequently repaid the amount within the same period. As of September 30, 2013, the Company was in compliance with the financial covenants in the Credit Agreement and no amounts were outstanding.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2013
COMMITMENTS AND CONTINGENCIES	'
	Note 11 COMMITMENTS AND CONTINGENCIES
	Lease Commitments. The Company leases office space and data centers under operating and capital lease agreements with original lease periods of up to 12 years which expire between 2013 and 2025.
	In May 2013, the Company entered into a 12 year operating lease agreement for four floors of the former New York Times building in New York City with a total expected minimum lease commitment of $125 million. The Company has the option to renew the lease for an additional five years. The lease requires monthly payments of approximately $1 million starting in July 2015 through June 2025.
	A summary of gross and net lease commitments as of September 30, 2013 was as follows (in millions):
		Gross Operating			Sublease			Net Operating
		Lease			Income			Lease
		Commitments						Commitments
	Three months ending December 31, 2013	$	39		$	(3	)	$	36
	Years ending December 31,
	2014		132			(11	)		121
	2015		108			(7	)		101
	2016		72			(1	)		71
	2017		53			—			53
	2018		36			—			36
	Due after 5 years		108			—			108
	Total gross and net lease commitments	$	548		$	(22	)	$	526
		Capital Lease
		Commitment
	Three months ending December 31, 2013	$	4
	Years ending December 31,
	2014		15
	2015		12
	2016		9
	2017		9
	2018		9
	Due after 5 years		4
	Gross lease commitment	$	62
	Less: interest		(16	)
	Net lease commitment included in capital lease and other long-term liabilities	$	46
	Affiliate Commitments. In connection with contracts to provide advertising services to Affiliates, the Company is obligated to make payments, which represent traffic acquisition costs (“TAC”), to its Affiliates. As of September 30, 2013, these commitments totaled $33 million, of which $22 million will be payable in the remainder of 2013, $9 million will be payable in 2014, $1 million will be payable in 2015, and $1 million will be payable in 2016.
	Intellectual Property Rights. The Company is committed to make certain payments under various intellectual property arrangements of up to $29 million through 2023.
	Other Commitments. In the ordinary course of business, the Company may provide indemnifications of varying scope and terms to customers, vendors, lessors, joint ventures and business partners, purchasers of assets or subsidiaries and other parties with respect to certain matters, including, but not limited to, losses arising out of the Company’s breach of agreements or representations and warranties made by the Company, services to be provided by the Company, intellectual property infringement claims made by third parties or, with respect to the sale of assets or a subsidiary, matters related to the Company’s conduct of the business and tax matters prior to the sale. In addition, the Company has entered into indemnification agreements with its directors and certain of its officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The Company has also agreed to indemnify certain former officers, directors, and employees of acquired companies in connection with the acquisition of such companies. The Company maintains director and officer insurance, which may cover certain liabilities arising from its obligation to indemnify its directors and officers, and former directors and officers of acquired companies, in certain circumstances. It is not possible to determine the aggregate maximum potential loss under these indemnification agreements due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement. Such indemnification agreements might not be subject to maximum loss clauses. Historically, the Company has not incurred material costs as a result of obligations under these agreements and it has not accrued any liabilities related to such indemnification obligations in the Company’s condensed consolidated financial statements.
	As of September 30, 2013, the Company did not have any relationships with unconsolidated entities or financial partnerships, such as entities often referred to as structured finance or special purpose entities, which would have been established for the purpose of facilitating off-balance sheet arrangements or other contractually narrow or limited purposes. Accordingly, the Company is not exposed to any financing, liquidity, market, or credit risk that could arise if the Company had engaged in such relationships. In addition, the Company identified no variable interests currently held in entities for which it is the primary beneficiary.
	See Note 16 — “Search Agreement with Microsoft Corporation” for a description of the Company’s Search and Advertising Services and Sales Agreement (the “Search Agreement”) and License Agreement with Microsoft Corporation (“Microsoft”).
	Legal Contingencies
	Intellectual Property and General Matters. From time to time, third parties assert patent infringement claims against the Company. Currently, the Company is engaged in lawsuits regarding patent issues and has been notified of other potential patent disputes. In addition, from time to time, the Company is subject to other legal proceedings and claims in the ordinary course of business, including claims of alleged infringement of trademarks, copyrights, trade secrets, and other intellectual property rights, claims related to employment matters, and a variety of other claims, including claims alleging defamation, invasion of privacy, or similar claims arising in connection with the Company’s e-mail, message boards, photo and video sites, auction sites, shopping services, and other communications and community features.
	Stockholder and Securities Matters. On June 14, 2007, a stockholder derivative action was filed in the United States District Court for the Central District of California by Jill Watkins against members of the board of directors (“Board”) and selected officers. The complaint filed by the plaintiff alleged breaches of fiduciary duties and corporate waste, similar to the allegations in a former class action relating to stock price declines during the period April 2004 to July 2006, and alleged violation of Section 10(b) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). On July 16, 2009, the plaintiff Watkins voluntarily dismissed the action against all defendants without prejudice. On July 17, 2009, plaintiff Miguel Leyte-Vidal, who had substituted in as plaintiff prior to the dismissal of the federal Watkins action, re-filed a stockholder derivative action in Santa Clara County Superior Court against members of the Board and selected officers. The Santa Clara County Superior Court derivative action purports to assert causes of action on behalf of the Company for violation of specified provisions of the California Corporations Code, for breaches of fiduciary duty regarding financial accounting and insider selling and for unjust enrichment. On October 23, 2013, the California Court of Appeal affirmed the Superior Court’s judgment in favor of all defendants following dismissal of plaintiff’s third amended complaint without leave to amend.
	Since May 31, 2011, several related stockholder derivative suits were filed in the Santa Clara County Superior Court (“California Derivative Litigation”) and the United States District Court for the Northern District of California (“Federal Derivative Litigation”) purportedly on behalf of the Company against certain officers and directors of the Company and third parties. The California Derivative Litigation was filed by plaintiffs Cinotto, Lassoff, Zucker, and Koo, and consolidated under the caption In re Yahoo! Inc. Derivative Shareholder Litigation on June 24, 2011 and September 12, 2011. The Federal Derivative Litigation was filed by plaintiffs Salzman, Tawila, and Iron Workers Mid-South Pension Fund and consolidated under the caption In re Yahoo! Inc. Shareholder Derivative Litigation on October 3, 2011. The plaintiffs allege breaches of fiduciary duties, corporate waste, mismanagement, abuse of control, unjust enrichment, misappropriation of corporate assets, or contribution and seek damages, equitable relief, disgorgement and corporate governance changes in connection with Alibaba Group’s restructuring of its subsidiary Alipay.com Co., Ltd. (“Alipay”) and related disclosures. On June 7, 2012, the courts approved stipulations staying the California Derivative Litigation pending resolution of the Federal Derivative Litigation, and deferring the Federal Derivative Litigation pending a ruling on the motion to dismiss filed by the defendants in the related stockholder class actions, which are discussed below. On September 13, 2013, the Company filed a motion to extend that stay pending resolution of the appeal filed by the plaintiffs in the related stockholder class actions.
	Since June 6, 2011, two purported stockholder class actions were filed in the United States District Court for the Northern District of California against the Company and certain officers and directors of the Company by plaintiffs Bonato and the Twin Cities Pipe Trades Pension Trust. In October 2011, the District Court consolidated the two actions under the caption In re Yahoo! Inc. Securities Litigation and appointed the Pension Trust Fund for Operating Engineers as lead plaintiff. In a consolidated amended complaint filed December 15, 2011, the lead plaintiff purports to represent a class of investors who purchased the Company’s common stock between April 19, 2011 and July 29, 2011, and alleges that during that class period, defendants issued statements that were materially false or misleading because they did not disclose information relating to Alibaba Group’s restructuring of Alipay. The complaint purports to assert claims for relief for violation of Section 10(b) and 20(a) of the Exchange Act and for violation of Rule 10b-5 thereunder, and seeks unspecified damages, injunctive and equitable relief, fees, and costs. On August 10, 2012, the court granted defendants’ motion to dismiss the consolidated amended complaint. Plaintiffs have appealed.
	On July 30, 2013, a stockholder derivative action captioned Zucker v. Loeb, et al. was filed in the Supreme Court of New York for the County of New York against current and former members of the Board, Third Point LLC, and entities related to Third Point LLC. The complaint filed by the plaintiff asserts claims for alleged breach of fiduciary duty, waste, and unjust enrichment in connection with the Company’s repurchase of 40 million shares of Company stock beneficially owned by Third Point LLC. The complaint seeks a judgment declaring that the defendants breached their fiduciary duties, an award of restitution, and corporate governance changes.
	Mexico Matter. On November 16, 2011, plaintiffs Worldwide Directories, S.A. de C.V. (“WWD”), and Ideas Interactivas, S.A. de C.V. (“Ideas”) filed an action in the 49th Civil Court of Mexico against the Company, Yahoo! de Mexico, S.A. de C.V. (“Yahoo! Mexico”), Yahoo International Subsidiary Holdings, Inc., and Yahoo Hispanic Americas LLC. The complaint alleged claims of breach of contract, breach of promise, and lost profits in connection with various commercial contracts entered into among the parties between 2002 and 2004, relating to a business listings service, and alleged total damages of approximately $2.75 billion. On December 7, 2011, Yahoo! Mexico filed a counterclaim against WWD for payments of approximately $2.6 million owed to Yahoo! Mexico for services rendered. On April 10, 2012, plaintiffs withdrew their claim filed against Yahoo International Subsidiary Holdings, Inc. and Yahoo Hispanic Americas LLC.
	On November 28, 2012, the 49th Civil Court of Mexico entered a non-final judgment against the Company and Yahoo! Mexico in the amount of USD $2.75 billion and a non-final judgment in favor of Yahoo! Mexico on its counterclaim against WWD in the amount of $2.6 million. The judgment against the Company and Yahoo! Mexico purported to leave open for determination in future proceedings certain other alleged damages that were not quantified in the judgment. The judgment was issued by a law clerk to the trial court judge who presided over the entire case during the trial court proceedings but stepped down from his position shortly before the judgment was entered.
	On December 12, 2012 and December 13, 2012, respectively, Yahoo! Mexico and the Company appealed the judgment to a three-magistrate panel of the Superior Court of Justice for the Federal District (the “Superior Court”). On May 15, 2013, the Superior Court reversed the judgment, overturned all monetary awards against the Company and reduced the monetary award against Yahoo! Mexico to $172,500. The Superior Court affirmed the award of $2.6 million in favor of Yahoo! Mexico on its counterclaim.
	Plaintiffs have appealed the Superior Court’s decision to the Mexican Federal Civil Collegiate Court for the First Circuit (“Civil Collegiate Court”). The Company has appealed the Superior Court’s decision not to award it statutory costs in the underlying proceeding. Yahoo! Mexico has appealed the Superior Court’s award of $172,500, the Superior Court’s decision not to award it additional moneys beyond the $2.6 million award on its counterclaims, and the Superior Court’s decision not to award it statutory costs. These appeals are all pending before the Civil Collegiate Court, where review is limited to whether the Superior Court’s decision is unconstitutional, unlawful, or both.
	The Company believes the plaintiffs’ claims are without legal or factual merit. First, the plaintiffs’ claims are based on agreements that were either terminated by agreement with releases or had expired or terminated in accordance with their terms, a non-binding letter of intent pursuant to which no definitive agreements were ever entered into by the parties, and correspondence that did not constitute agreements. Second, the loss of profits of the type claimed by plaintiffs are not awardable under Mexico law because they were not a direct and immediate consequence of a breach of contract. Of the $2.75 billion in total damages alleged by plaintiffs, more than $2.4 billion were for loss of profits. Third, the plaintiffs’ alleged damages and loss of profits were further precluded by the agreements at issue through, among other things, contractual and legal limitations of liability. Fourth, the plaintiffs’ pleadings in the complaint, as well as documentary evidence filed by the plaintiffs in support of their allegations, were generally deficient to support or establish plaintiffs’ claims. Fifth, the decision failed to consider substantially all of the defenses asserted by the Company and Yahoo! Mexico. Finally, the Company believes that the law clerk who entered the judgment lacked the requisite authority to issue the judgment.
	The Company has not recorded an accrual for the judgment, which was reversed, as explained above. The Company cannot assure the ultimate outcome of the pending or further appeals.
	The Company has determined, based on current knowledge, that the amount or range of reasonably possible losses, including reasonably possible losses in excess of amounts already accrued, is not reasonably estimable with respect to certain matters described above. The Company has also determined, based on current knowledge, that the aggregate amount or range of losses that are estimable with respect to the Company’s legal proceedings, including the matters described above other than the Mexico matter, would not have a material adverse effect on the Company’s consolidated financial position, results of operations or cash flows. Amounts accrued as of December 31, 2012 and September 30, 2013 were not material. The ultimate outcome of legal proceedings involves judgments, estimates and inherent uncertainties, and cannot be predicted with certainty. In the event of a determination adverse to Yahoo, its subsidiaries, directors, or officers in these matters, the Company may incur substantial monetary liability, and be required to change its business practices. Either of these events could have a material adverse effect on the Company’s financial position, results of operations, or cash flows. The Company may also incur substantial legal fees, which are expensed as incurred, in defending against these claims.

STOCKHOLDERS_EQUITY_AND_EMPLOY

STOCKHOLDERS' EQUITY AND EMPLOYEE BENEFITS	9 Months Ended
	Sep. 30, 2013
STOCKHOLDERS' EQUITY AND EMPLOYEE BENEFITS	'
	Note 12 STOCKHOLDERS’ EQUITY AND EMPLOYEE BENEFITS
	Employee Stock Purchase Plan. As of September 30, 2013, there was $5 million of unamortized stock-based compensation expense related to the Company’s Employee Stock Purchase Plan, which will be recognized over a weighted average period of 0.6 years.
	Stock Options. The Company’s 1995 Stock Plan, the Directors’ Plan, stock-based awards assumed through acquisitions, and the Tumblr equity holdback are collectively referred to as the “Plans.” Stock option activity under the Company’s Plans for the nine months ended September 30, 2013 is summarized as follows (in thousands, except per share amounts):
			Shares			Weighted Average
						Exercise Price Per
						Share
	Outstanding at December 31, 2012			38,092		$	21.42
	Options granted			42		$	26.93
	Options assumed			1,121		$	7.39
	Options exercised			(8,169	)	$	17.66
	Options expired			(3,250	)	$	29.73
	Options cancelled/forfeited			(1,013	)	$	15.2
	Outstanding at September 30, 2013			26,823		$	21.24
	As of September 30, 2013, there was $22 million of unamortized stock-based compensation expense related to unvested stock options, which is expected to be recognized over a weighted average period of 1.5 years.
	The fair value of option grants is determined using the Black-Scholes option pricing model with the following weighted average assumptions:
			Stock Options						Purchase Plan (1)
			Three Months Ended						Three Months Ended
			September 30,			September 30,			September 30,			September 30,
			2012			2013			2012			2013
	Expected dividend yield			0	%		0	%		0	%		0	%
	Risk-free interest rate(2)			0.6	%		0.8	%		0.8	%		0.1	%
	Expected volatility			31.2	%		34.8	%		31.2	%		32	%
	Expected life (in years)(2)			4			3.17			1.86			0.25
			Stock Options						Purchase Plan (1)
			Nine Months Ended						Nine Months Ended
			September 30,			September 30,			September 30,			September 30,
			2012			2013			2012			2013
	Expected dividend yield			0	%		0	%		0	%		0	%
	Risk-free interest rate(2)			0.7	%		0.6	%		1.1	%		0.1	%
	Expected volatility			31.9	%		32.4	%		33.1	%		30.3	%
	Expected life (in years)(2)			4.03			3.47			1.46			0.25
	(1)	Assumptions for the Employee Stock Purchase Plan relate to the annual average of the enrollment periods. During the year ended December 31, 2012, enrollment was permitted in May and November of each year. Beginning in 2013, enrollment is permitted in February, May, August, and November of each year.
	(2)	Beginning in November 2012, the Employee Stock Purchase Plan was modified to consist of three-month offering periods.
	Restricted Stock and Restricted Stock Units. Restricted stock and restricted stock unit activity under the Plans for the nine months ended September 30, 2013 is summarized as follows (in thousands, except per share amounts):
			Shares			Weighted Average
						Grant Date
						Fair Value
						Per Share
	Awarded and unvested at December 31, 2012(*)			33,801		$	17.63
	Granted(*)			28,140		$	23.34
	Assumed			2,364		$	26.24
	Vested			(11,759	)	$	15.05
	Forfeited			(5,805	)	$	17.33
	Awarded and unvested at September 30, 2013(*)			46,741		$	22.19
	(*)	Includes the maximum number of shares issuable under the Company’s performance-based restricted stock unit awards.
	As of September 30, 2013, there was $542 million of unamortized stock-based compensation expense related to unvested restricted stock and restricted stock units, which is expected to be recognized over a weighted average period of 2.4 years.
	During the nine months ended September 30, 2012 and 2013, 8.8 million shares and 11.8 million shares, respectively, that were subject to previously granted restricted stock units vested. These vested restricted stock units were net share settled. During the nine months ended September 30, 2012 and 2013, the Company withheld 3.2 million shares and 4.3 million shares, respectively, based upon the Company’s closing stock price on the vesting date to settle the employees’ minimum statutory obligation for the applicable income and other employment taxes. The Company then remitted cash to the appropriate taxing authorities.
	Total payments for the employees’ tax obligations to the relevant taxing authorities were $48 million and $106 million, respectively, for the nine months ended September 30, 2012 and 2013 and are reflected as a financing activity within the condensed consolidated statements of cash flows. The payments were used for tax withholdings related to the net share settlements of restricted stock units. The payments had the effect of share repurchases by the Company as they reduced the number of shares that would have otherwise been issued on the vesting date and were recorded as a reduction of additional paid-in capital.
	Performance-Based Executive Incentive Equity Awards. The financial performance stock options awarded by the Company in November 2012 include multiple performance periods. In January 2013, the Compensation and Leadership Development Committee of the Board (the “Compensation Committee”) established performance goals under these stock options for the first performance period (the six months ended June 30, 2013) and the second performance period (the full year ending December 31, 2013). These options are held by Ms. Mayer, Mr. de Castro and Mr. Goldman (the first performance period for Mr. Goldman is the full year ending December 31, 2013). The number of stock options that ultimately vest for each performance period will range from 0 percent to 100 percent of the target amount for such period stated in each executive’s award agreement based on the Company’s performance. The financial performance metrics (and their weightings) under the performance options are revenue ex-TAC (50 percent), operating income (30 percent) and free cash flow (20 percent). The financial performance goals for each metric are established at the beginning of each performance period and, accordingly, the portion (or “tranche”) of the award related to each performance period is treated as a separate grant for accounting purposes. The grant date fair values of the first and second tranches of the November 2012 financial performance stock options were $12 million and $14 million, respectively, and are being recognized over six and twelve month service periods, respectively. The Company began recording stock-based compensation expense for these tranches in January 2013, when the financial performance goals were established and approved.
	In February 2013, the Compensation Committee approved additional long-term performance-based incentive equity awards to Ms. Mayer and other senior officers. These restricted stock units generally will be eligible to vest in equal annual tranches over four years (three years for Ms. Mayer) based on the Company’s attainment of annual financial performance goals as well as the executive’s continued employment through the vesting date. The number of restricted stock units that ultimately vest each year will range from 0 percent to 200 percent of the annual target amount stated in each executive’s award agreement based on the Company’s performance. The annual financial performance metrics and goals are established at the beginning of each fiscal year and, accordingly, the tranche of the award related to each annual performance period goal is treated as a separate annual grant for accounting purposes. In February 2013, financial performance metrics and goals were established for the first performance period (the fiscal year ending December 31, 2013). The financial performance metrics (and their weightings) for fiscal year 2013 are revenue ex-TAC (60 percent), operating income (20 percent) and free cash flow (20 percent). The grant date fair value of the first tranche of the February 2013 annual financial performance restricted stock unit grants was $9 million and is being recognized over a one-year service period.
	Stock Repurchases. In May 2012, the Board authorized a stock repurchase program allowing the Company to repurchase up to $5 billion of its outstanding shares of common stock from time to time. The May 2012 repurchase program, according to its terms, will expire in June 2015 unless revoked earlier by the Board. The aggregate amount remaining available under the May 2012 repurchase program was approximately $324 million at September 30, 2013. Repurchases under the repurchase program may take place in the open market or in privately negotiated transactions, including structured and derivative transactions such as accelerated share repurchase transactions, and may be made under a Rule 10b5-1 plan. During the nine months ended September 30, 2013, the Company repurchased approximately 123 million shares of its common stock under this stock repurchase program at an average price of $25.41 per share for a total of $3.1 billion. These repurchases included the Company’s repurchase of 40 million shares of its common stock beneficially owned by Third Point LLC on July 25, 2013. These shares were repurchased pursuant to a Purchase Agreement entered into on July 22, 2013, prior to the market opening for trading in Yahoo stock, at $29.11 per share, which was the closing price of the Company’s common stock on July 19, 2013. The total purchase price for these shares was $1.164 billion. The repurchase transaction was funded primarily with cash as well as borrowings of $150 million under the Company’s unsecured revolving credit facility.

RESTRUCTURING_CHARGES_REVERSAL

RESTRUCTURING CHARGES (REVERSALS), NET	9 Months Ended
	Sep. 30, 2013
RESTRUCTURING CHARGES (REVERSALS), NET	'
	Note 13 RESTRUCTURING CHARGES (REVERSALS), NET
	Restructuring charges (reversals), net was comprised of the following (in thousands):
		Three Months Ended September 30, 2012												Nine Months Ended September 30, 2012
		Restructuring			Q2’12			Q4’12			Total			Restructuring			Q2’12			Q4’12			Total
		Plans Prior			Restructuring			Korea						Plans Prior			Restructuring			Korea
		to			Plan			Business						to			Plan			Business
		2012						Closure						2012						Closure
	Employee severance pay and related costs	$	(44	)	$	11,511		$	—		$	11,467		$	3,617		$	102,577		$	—		$	106,194
	Non-cancelable lease, contract terminations, and other charges		2,104			9,332			—			11,436			6,360			9,949			—			16,309
	Other non-cash charges		—			1,824			—			1,824			—			40,462			—			40,462
	Sub-total before reversal of stock-based compensation expense		2,060			22,667			—			24,727			9,977			152,988			—			162,965
	Reversal of stock-based compensation expense for forfeitures		—			—			—			—			—			(3,429	)		—			(3,429	)
	Restructuring charges, net	$	2,060		$	22,667		$	—		$	24,727		$	9,977		$	149,559		$	—		$	159,536
		Three Months Ended September 30, 2013												Nine Months Ended September 30, 2013
		Restructuring			Q2’12			Q4’12			Total			Restructuring			Q2’12			Q4’12			Total
		Plans Prior			Restructuring			Korea						Plans Prior			Restructuring			Korea
		to			Plan			Business						to			Plan			Business
		2012						Closure						2012						Closure
	Employee severance pay and related costs	$	(20	)	$	(2,807	)	$	—		$	(2,827	)	$	(459	)	$	(15,784	)	$	(103	)	$	(16,346	)
	Non-cancelable lease, contract terminations, and other charges		2,217			33			1			2,251			11,652			131			(44	)		11,739
	Other non-cash charges		—			—			—			—			—			—			547			547
	Restructuring charges (reversals), net	$	2,197		$	(2,774	)	$	1		$	(576	)	$	11,193		$	(15,653	)	$	400		$	(4,060	)
	Although the Company does not allocate restructuring charges to its segments, the amounts of the restructuring charges relating to each segment are presented below.
	Restructuring Plans Prior to 2012. Prior to 2012, the Company implemented workforce reductions, a strategic realignment, and consolidation of certain real estate facilities and data centers to reduce its cost structure, align resources with its product strategy, and improve efficiency. During the three and nine months ended September 30, 2012, the Company recorded total pre-tax cash charges of $2 million and $10 million, respectively, in severance, facility, and other related costs under these restructuring plans, the majority of which related to the Americas segment.
	During the three and nine months ended September 30, 2013, the Company incurred total pre-tax cash charges of $2 million and $11 million, respectively, in severance, facility, and other related costs under these restructuring plans. The $2 million recorded for the three months ended September 30, 2013 was primarily related to the Americas segment. Of the $11 million recorded for the nine months ended September 30, 2013, $7 million related to the Americas segment and $4 million related to the EMEA segment.
	Q2’12 Restructuring Plan. During the second quarter of 2012, the Company began implementing the Q2’12 Restructuring Plan to reduce its worldwide workforce by approximately 2,000 employees and to consolidate certain real estate and data center facilities. During the three months ended September 30, 2012, the Company recorded total pre-tax cash charges of $35 million in severance- and facility-related costs and $2 million in non-cash facility and other asset impairment charges. Those total pre-tax charges were offset by a reversal of $14 million for adjustments to original estimates in severance-related costs, primarily as a result of redeployments and voluntary resignations of employees prior to their planned severance dates. Of the $23 million in restructuring charges, net recorded in the three months ended September 30, 2012, $11 million related to the Americas segment and $12 million related to the EMEA segment. During the nine months ended September 30, 2012, the Company recorded total pre-tax cash charges of $127 million in severance- and facility-related costs and $40 million in non-cash facility and other asset impairment charges under this restructuring plan. The total pre-tax charges during the nine months ended September 30, 2012 were offset by a reversal of $17 million for adjustments to original estimates. Of the $150 million in restructuring charges, net, recorded in the nine months ended September 30, 2012, $97 million related to the Americas segment, $47 million related to the EMEA segment, and $6 million related to the Asia Pacific segment.
	During the three months ended September 30, 2013, the Company recorded a net reversal of $3 million for severance-related cost reversals due to changes to original estimates and redeployments and voluntary resignations of employees prior to their planned severance dates. During the nine months ended September 30, 2013, the Company recorded $6 million in severance- and facility-related costs which were offset by a credit of $22 million for severance-related reversals due to adjustments to original estimates as a result of redeployments and voluntary resignations of employees prior to their planned severance dates. Of the $3 million credit in restructuring charges, net, recorded in the three months ended September 30, 2013, $2 million related to the EMEA segment and $1 million related to the Asia Pacific segment. Of the $16 million credit in restructuring charges, net, recorded in the nine months ended September 30, 2013, $8 million related to the Americas segment, $7 million related to the EMEA segment, and $1 million related to the Asia Pacific segment.
	Q4’12 Korea Business Closure. During the fourth quarter of 2012, the Company decided to close its Korea business by the end of 2012 to streamline its operations and focus its resources. During both the three and nine months ended September 30, 2013, the Company recorded net pre-tax charges of less than $1 million in severance, facility and contract termination costs related to the Asia Pacific segment.
	Restructuring Accruals. The $30 million restructuring liability as of September 30, 2013 consisted of $2 million for employee severance pay expenses, which the Company expects to pay out by the end of the fourth quarter of 2013, and $28 million relating to non-cancelable lease and contract termination costs, which the Company expects to pay over the terms of the related obligations which extend to the fourth quarter of 2021.
	The Company’s restructuring accrual activity for the nine months ended September 30, 2013 is summarized as follows (in thousands):
		Restructuring			Q2’12			Q4’12			Total
		Plans Prior to			Restructuring			Korea Business
		2012			Plan			Closure
	Balance as of January 1, 2013	$	27,716		$	35,049		$	10,102		$	72,867
	Employee severance pay and related costs		28			6,271			443			6,742
	Non-cancelable lease, contract termination, and other charges		12,127			131			1,227			13,485
	Other non-cash charges		—			—			547			547
	Changes in estimates and reversals of previous charges		(962	)		(22,055	)		(1,817	)		(24,834	)
	Restructuring charges (reversals), net for the nine months ended September 30, 2013	$	11,193		$	(15,653	)	$	400		$	(4,060	)
	Cash paid		(13,424	)		(15,358	)		(9,045	)		(37,827	)
	Other non-cash charges		—			—			(547	)		(547	)
	Foreign currency		142			(250	)		(171	)		(279	)
	Balance as of September 30, 2013	$	25,627		$	3,788		$	739		$	30,154
	Restructuring accruals by segment consisted of the following (in thousands):
		December 31,			September 30,
		2012			2013
	Americas	$	42,689		$	20,190
	EMEA		18,144			8,851
	Asia Pacific		12,034			1,113
	Total restructuring accruals	$	72,867		$	30,154

INCOME_TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2013
INCOME TAXES	'
	Note 14 INCOME TAXES
	The Company’s effective tax rate is the result of the mix of income earned in various tax jurisdictions that apply a broad range of income tax rates. Historically, the Company’s provision for income taxes has differed from the tax computed at the U.S. federal statutory income tax rate due to state taxes, the effect of non-U.S. operations, non-deductible stock-based compensation expense and adjustments to unrecognized tax benefits.
	The effective tax rate reported for the three months ended September 30, 2013 was 32 percent compared to 37 percent for the same period in 2012. The effective tax rate reported for the nine months ended September 30, 2013 was 24 percent compared to 37 percent for the same period in 2012. The effective tax rates for the three and nine months ended September 30, 2012 were higher than for the corresponding periods in 2013, because they included the tax expense associated with the Company’s taxable gain from the sale of Alibaba Group Shares in September 2012. The lower effective tax rates for the three and nine months ended September 30, 2013 were also related to a reduction of tax reserves that were recorded as tax audits were favorably settled and a tax benefit from the resolution of certain tax matters associated with a one-time foreign earnings distribution made in 2012 as described below.
	The conclusion of the 2005 and 2006 IRS tax audit and certain foreign tax audits had the effect of increasing the foreign tax credits available to offset the tax from the distribution of foreign earnings made during the three months ended September 30, 2012 as described below. The increased foreign tax credits and the tax benefit relating to the resolution of certain tax matters associated with a one-time foreign earnings distribution made during the quarter ended September 30, 2012 mentioned above, resulted in a tax benefit during the nine months ended September 30, 2013 of approximately $31 million.
	The federal research and development credit expired on December 31, 2011. On January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law. Under this act, the federal research and development credit was retroactively extended for amounts paid or incurred after December 31, 2011 and before January 1, 2014. This change resulted in a 2012 tax benefit of approximately $11 million, which was recognized over the nine months ended September 30, 2013.
	The U.S. Department of the Treasury issued final regulations on the deduction and capitalization of expenditures related to tangible property for income tax purposes. These regulations apply to the Company’s tax year beginning on January 1, 2014. The Company is currently assessing the financial statement impact of these regulations.
	In connection with a review of the Company’s cash position and anticipated cash needs for investment in the Company’s core business, including potential acquisitions, capital expenditures and stock repurchases, the Company made a one-time repatriation of cash from certain of its consolidated foreign subsidiaries in 2012. The remaining undistributed foreign earnings of approximately $2 billion plus all subsequent earnings will continue to be indefinitely reinvested going forward. As of September 30, 2013, those earnings are approximately $2.5 billion in total and are principally related to Yahoo Japan.
	During the nine months ended September 30, 2013, the Company settled the income tax examination for the 2005 and 2006 returns with the IRS Appeals Division. That settlement resulted in a reduction of tax reserves. The income tax examination for the 2007 and 2008 returns is currently under protest with the IRS Appeals Division relating to certain proposed adjustments to the Company’s intercompany transfer pricing methodology. The Company’s 2009 and 2010 returns are currently under IRS examination.
	As of September 30, 2013, the Company’s 2005 through 2008 tax returns are also under various stages of audit by the California Franchise Tax Board. While the California Franchise Tax Board has not reached any conclusions on the 2007 and 2008 returns, the Company has protested the proposed California Franchise Tax Board’s adjustments to the 2005 and 2006 returns. The Company is also in various stages of examination and appeal in connection with its taxes in foreign jurisdictions, which generally span tax years 2005 through 2011.
	The Company’s gross amount of unrecognized tax benefits as of September 30, 2013 was $703 million, of which $621 million is recorded on the condensed consolidated balance sheets. The gross unrecognized tax benefits as of September 30, 2013 decreased by $24 million from the recorded balance as of December 31, 2012. It is difficult to determine when the examinations will be settled or their final outcomes; however, certain audits in various jurisdictions related to multinational income tax issues are expected to be resolved in the foreseeable future. As a result, it is reasonably possible that the unrecognized tax benefits could be reduced by up to approximately $24 million in the next twelve months. The Company believes that it has adequately provided for any reasonably foreseeable adjustment and that any settlement will not have a material adverse effect on the Company’s consolidated financial position, results of operations, or cash flows.
	The Company may have additional tax liabilities in China related to the sale to Alibaba Group of 523 million Alibaba Group Shares that took place during the year ended December 31, 2012. Any taxes assessed and paid in China are expected to be ultimately offset and recovered in the U.S.
	During the year ended December 31, 2012, tax authorities from the Brazilian State of Sao Paulo assessed certain indirect taxes against the Company’s Brazilian subsidiary, Yahoo! do Brasil Internet Ltda., related to online advertising services. The assessment totaling approximately $85 million is for calendar years 2008 and 2009. The Company currently believes the assessment is without merit. The Company does not believe that it is probable the assessment will be sustained upon appeal and, accordingly, has not recorded an accrual for the assessment.

SEGMENTS

SEGMENTS	9 Months Ended
	Sep. 30, 2013
SEGMENTS	'
	Note 15 SEGMENTS
	The Company continues to manage its business geographically. The primary areas of measurement and decision-making are currently Americas, EMEA (Europe, Middle East, and Africa), and Asia Pacific. Management relies on an internal reporting process that provides revenue ex-TAC, which is defined as revenue less TAC, direct costs excluding TAC by segment, and consolidated income from operations for making decisions related to the evaluation of the financial performance of, and allocating resources to, the Company’s segments. Tumblr, which the Company acquired during June 2013, is included as part of the Americas for segment reporting purposes.
	The following tables present summarized information by segment (in thousands):
			Three Months Ended					Nine Months Ended
			September 30,		September 30,			September 30,		September 30,
			2012		2013			2012		2013
	Revenue by segment:
	Americas		$	843,731	$	850,935		$	2,501,515	$	2,521,667
	EMEA			96,473		89,156			358,534		281,367
	Asia Pacific			261,528		198,882			780,710		611,551
	Total Revenue		$	1,201,732	$	1,138,973		$	3,640,759	$	3,414,585
	TAC by segment:
	Americas		$	41,289	$	36,435		$	130,154	$	111,077
	EMEA			17,399		9,929			97,248		32,837
	Asia Pacific			54,141		12,100			166,543		44,934
	Total TAC		$	112,829	$	58,464		$	393,945	$	188,848
	Revenue ex-TAC by segment:
	Americas		$	802,442	$	814,500		$	2,371,361	$	2,410,590
	EMEA			79,074		79,227			261,286		248,530
	Asia Pacific			207,387		186,782			614,167		566,617
	Total Revenue ex-TAC		$	1,088,903	$	1,080,509		$	3,246,814	$	3,225,737
	Direct costs by segment(1):
	Americas			189,345		171,285			550,080		513,677
	EMEA			39,167		39,922			120,665		119,766
	Asia Pacific			56,329		47,583			164,068		152,264
	Global operating costs(2)(3)			396,269		490,594			1,228,686		1,354,118
	Depreciation and amortization			169,511		158,216			480,498		480,797
	Stock-based compensation expense			61,366		80,726			166,903		193,467
	Restructuring charges (reversals), net			24,727		(576	)		159,536		(4,060	)
	Income from operations		$	152,189	$	92,759		$	376,378	$	415,708
	(1)	Direct costs for each segment include cost of revenue—other as well as other operating expenses that are directly attributable to the segment such as employee compensation expense (excluding stock-based compensation expense), local sales and marketing expenses, and facilities expenses.
	(2)	Global operating costs include product development, service engineering and operations, general and administrative, and other corporate expenses that are managed on a global basis and that are not directly attributable to any segment.
	(3)	The net cost reimbursements from Microsoft pursuant to the Search Agreement are primarily included in global operating costs.
			Three Months Ended					Nine Months Ended
			September 30,		September 30,			September 30,		September 30,
			2012		2013			2012		2013
	Capital expenditures, net:
	Americas		$	122,812	$	70,044		$	302,139	$	210,521
	EMEA			9,238		2,817			22,599		8,481
	Asia Pacific			7,815		4,792			31,049		10,308
	Total capital expenditures, net		$	139,865	$	77,653		$	355,787	$	229,310
			December 31,		September 30,
			2012		2013
	Property and equipment, net:
	Americas:
	U.S		$	1,483,225	$	1,383,769
	Other			1,869		1,428
	Total Americas		$	1,485,094	$	1,385,197
	EMEA			59,416		48,183
	Asia Pacific			141,335		102,982
	Total property and equipment, net		$	1,685,845	$	1,536,362
	See Note 13 —“Restructuring Charges (Reversals), Net” for additional information regarding segments.
	Enterprise Wide Disclosures:
	The following table presents revenue for groups of similar services (in thousands):
			Three Months Ended					Nine Months Ended
			September 30,		September 30,			September 30,		September 30,
			2012		2013			2012		2013
	Display		$	506,002	$	469,932		$	1,552,191	$	1,396,745
	Search			472,537		435,192			1,403,903		1,278,081
	Other			223,193		233,849			684,665		739,759
	Total revenue		$	1,201,732	$	1,138,973		$	3,640,759	$	3,414,585
			Three Months Ended					Nine Months Ended
			September 30,		September 30,			September 30,		September 30,
2012			2013		2012			2013
Revenue:
U.S.		$	800,984	$	812,048		$	2,379,955	$	2,401,527
International			400,748		326,925			1,260,804		1,013,058
Total revenue		$	1,201,732	$	1,138,973		$	3,640,759	$	3,414,585
Revenue is attributed to individual countries according to the online property that generated the revenue. No single foreign country was material to revenue for the three or nine months ended September 30, 2012 and 2013.

SEARCH_AGREEMENT_WITH_MICROSOF

SEARCH AGREEMENT WITH MICROSOFT CORPORATION	9 Months Ended
	Sep. 30, 2013
SEARCH AGREEMENT WITH MICROSOFT CORPORATION	'
	Note 16 SEARCH AGREEMENT WITH MICROSOFT CORPORATION
	On December 4, 2009, the Company entered into the Search Agreement with Microsoft, which provides for Microsoft to be the exclusive algorithmic and paid search services provider on Yahoo Properties and non-exclusive provider of such services on Affiliate sites. The Company also entered into a License Agreement with Microsoft. Under the License Agreement, Microsoft acquired an exclusive 10-year license to the Company’s core search technology and has the ability to integrate this technology into its existing Web search platforms. On February 18, 2010, the Company received regulatory clearance from both the U.S. Department of Justice and the European Commission and on February 23, 2010 the Company commenced implementation of the Search Agreement on a market-by-market basis. Under the Search Agreement, the Company is the exclusive worldwide relationship sales force for both companies’ premium search advertisers, which include advertisers meeting certain spending or other criteria, advertising agencies that specialize in or offer search engine marketing services and their clients, and resellers and their clients seeking assistance with their paid search accounts. The term of the Search Agreement is 10 years from February 23, 2010, subject to earlier termination as provided in the Search Agreement. Approximately 27 percent and 24 percent of the Company’s revenue for the three and nine months ended September 30, 2012, respectively, was attributable to the Search Agreement, and approximately 31 percent and 30 percent of the Company’s revenue for the three and nine months ended September 30, 2013, respectively, was attributable to the Search Agreement.
	During the first five years of the term of the Search Agreement, in the transitioned markets, the Company is entitled to receive 88 percent of the revenue generated from Microsoft’s services on Yahoo Properties (the “Revenue Share Rate”) and the Company is also entitled to receive 88 percent of the revenue generated from Microsoft’s services on Affiliate sites after the Affiliate’s share of revenue. For new Affiliates during the term of the Search Agreement, and for all Affiliates after the first five years of such term, the Company will receive 88 percent of the revenue generated from Microsoft’s services on Affiliate sites after the Affiliate’s share of revenue and certain Microsoft costs are deducted. On February 23, 2015 (the fifth anniversary of the date that implementation of the Search Agreement commenced), Microsoft will have the option to terminate the Company’s sales exclusivity for premium search advertisers. If Microsoft exercises this option, the Revenue Share Rate will increase to 93 percent for the remainder of the term of the Search Agreement, unless the Company exercises its option to retain the Company’s sales exclusivity, in which case the Revenue Share Rate would be reduced to 83 percent for the remainder of the term. If Microsoft does not exercise such option, the Revenue Share Rate will be 90 percent for the remainder of the term of the Search Agreement. In the transitioned markets, the Company reports as revenue the 88 percent revenue share as the Company is not the primary obligor in the arrangement with the advertisers and publishers. The underlying search advertising services are provided by Microsoft. As of December 31, 2012 and September 30, 2013, the Company had collected total amounts of nil and $24 million, respectively, on behalf of Microsoft and Affiliates, which was included in cash and cash equivalents with a corresponding liability in accrued expenses and other current liabilities. The Company’s 88 percent share in connection with the Search Agreement, which is included in accounts receivable, net, was $258 million and $251 million as of December 31, 2012 and September 30, 2013, respectively.
	Under the Search Agreement, for each market, Microsoft generally guarantees Yahoo’s revenue per search (“RPS Guarantee”) on Yahoo Properties only for 18 months after the transition of paid search services to Microsoft’s platform in that market based on the difference in revenue per search between the pre-transition and post-transition periods and certain other factors. The Company records the RPS Guarantee as search revenue in the quarter the amount becomes fixed, which is typically the quarter in which the associated shortfall in revenue per search occurred. In the fourth quarter of 2011, Microsoft agreed to extend the RPS Guarantee in the U.S. and Canada through March 2013, and in the second quarter of 2013, Microsoft extended the RPS Guarantee in the U.S. through March 2014. In June 2013, Microsoft and Yahoo agreed upon the RPS Guarantee payment amounts to be paid to the Company for the quarters ended December 31, 2012, March 31, 2013 and June 30, 2013. The Company also agreed to fixed quarterly payments in lieu of the RPS Guarantee in the U.S. for the quarters ending September 30, 2013, December 31, 2013 and March 31, 2014. In addition, the Company agreed to waive its right to receive any future RPS Guarantee payments in all other markets except Taiwan and Hong Kong.
	The Company completed the transition of its algorithmic and paid search platforms to the Microsoft platform in the U.S. and Canada in the fourth quarter of 2010. In 2011, the Company completed the transition of algorithmic search in all other markets and the transition of paid search in India. In 2012, the Company completed the transition of paid search in most of the EMEA markets as well as six markets in Latin America. In the second quarter of 2013, the Company completed the transition of paid search in Brazil. In the third quarter of 2013, the Company completed the transition of paid search in six markets in Southeast Asia. The market-by-market transition of the Company’s paid search platform to Microsoft’s platform and the migration of paid search advertisers and publishers to Microsoft’s platform are expected to continue through 2013 and possibly into 2014.
	In September 2013, the Company advised Microsoft that we were delaying the transition of paid search in Taiwan and Hong Kong. Microsoft disagreed with the delay and initiated an emergency arbitration under the Search Agreement. The arbitrator enjoined the Company from continuing the delay and directed the Company to complete the transition of Taiwan and Hong Kong in October and November, respectively. The Company sought to vacate the arbitrator’s award in the United States District Court for the Southern District of New York, but the District Court issued an order denying the Company’s petition to vacate. The Company then filed a notice of appeal to the United States Court of Appeals for the Second Circuit, together with a motion to stay enforcement of the District Court’s order pending the appeal. The Second Circuit granted a temporary stay of enforcement of the District Court’s order, but on November 7, 2013, denied the continuation of the stay pending appeal. The Company is working with Microsoft on a transition schedule.
	From February 23, 2010 until the applicable services are fully transitioned to Microsoft in all markets, Microsoft is required under the Search Agreement to reimburse the Company for the costs of operating algorithmic and paid search services subject to specified exclusions and limitations. The Company’s results reflect search operating cost reimbursements from Microsoft under the Search Agreement of $17 million and $51 million for the three and nine months ended September 30, 2012, respectively, and $11 million and $42 million for the three and nine months ended September 30, 2013, respectively. Search operating cost reimbursements began during the quarter ended March 31, 2010 and will, subject to specified exclusions and limitations, continue until the Company has fully transitioned to Microsoft’s platform.
	Reimbursement receivables are recorded as the reimbursable costs are incurred and are applied against the operating expense categories in which the costs were incurred. Of the total amounts incurred during the year ended December 31, 2012 and the nine months ended September 30, 2013, the total reimbursements not yet received from Microsoft of $5 million and $8 million, respectively, were classified as part of prepaid expenses and other current assets on the Company’s condensed consolidated balance sheets as of December 31, 2012 and September 30, 2013, respectively.

SUBSEQUENT_EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2013
SUBSEQUENT EVENTS	'
	Note 17 SUBSEQUENT EVENTS
	Stock Repurchase Transactions. From October 1, 2013 through November 12, 2013, the Company repurchased approximately 1.2 million shares of its common stock at an average price of $33.37 per share, for a total of $41 million.
	Net Investment Hedge. In October 2013, the Company received $158 million in cash for the settlement of certain foreign exchange forward contracts designated as net investment hedges reducing the outstanding notional amount to $2.3 billion.
	Amendment to Share Repurchase and Preference Share Sale Agreement with Alibaba Group. The Company, Yahoo! Hong Kong Holdings Limited (“YHK”) and Alibaba Group entered into a Second Amendment to the Share Repurchase and Preference Share Sale Agreement, dated as of October 14, 2013. The amendment reduced the maximum number of Shares of Alibaba Group that Yahoo is required to sell in connection with a Qualified IPO of Alibaba Group from 261.5 million Shares to 208.0 million Shares.
	Amendment No. 1 to Credit Agreement. On October 10, 2013, the Company entered into Amendment No. 1 to its Credit Agreement. Amendment No. 1 extends the termination date of the Credit Agreement from October 18, 2013 to October 9, 2014. The Credit Agreement, as amended, continues to provide for a $750 million unsecured revolving credit facility, subject to increase by up to $250 million in accordance with its terms. There are no borrowings currently outstanding under the Credit Agreement.
	Patent Sale Agreement. Subsequent to September 30, 2013, the Company entered into a patent sale agreement pursuant to which the Company sold certain patents for an aggregate consideration of $70 million.

THE_COMPANY_AND_SUMMARY_OF_SIG1

THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2013
Basis of Presentation	'
	Basis of Presentation. The condensed consolidated financial statements include the accounts of Yahoo! Inc. and its majority-owned or otherwise controlled subsidiaries. All significant intercompany accounts and transactions have been eliminated. Investments in entities in which the Company can exercise significant influence, but does not own a majority equity interest or otherwise control, are accounted for using the equity method and are included as investments in equity interests on the condensed consolidated balance sheets. The Company has included the results of operations of acquired companies from the date of the acquisition.
	The accompanying unaudited condensed consolidated interim financial statements reflect all adjustments, consisting of only normal recurring items, which, in the opinion of management, are necessary for a fair statement of the results of operations for the periods shown. The results of operations for such periods are not necessarily indicative of the results expected for the full year or for any future periods.
	The preparation of consolidated financial statements in conformity with generally accepted accounting principles (“GAAP”) in the United States (“U.S.”) requires management to make estimates, judgments, and assumptions that affect the reported amounts of assets, liabilities, revenue, and expenses and the related disclosure of contingent assets and liabilities. On an ongoing basis, the Company evaluates its estimates, including those related to revenue, the useful lives of long-lived assets including property and equipment and intangible assets, investment fair values, stock-based compensation, goodwill, income taxes, contingencies, and restructuring charges. The Company bases its estimates of the carrying value of certain assets and liabilities on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, when these carrying values are not readily available from other sources. Actual results may differ from these estimates.
	These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The condensed consolidated balance sheet as of December 31, 2012 was derived from the Company’s audited financial statements for the year ended December 31, 2012, but does not include all disclosures required by U.S. GAAP. However, the Company believes the disclosures are adequate to make the information presented not misleading.

INVESTMENTS_AND_FAIR_VALUE_MEA1

INVESTMENTS AND FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Investments in Available for Sale Securities	'
	The following tables summarize the investments in available-for-sale securities (in thousands):
			December 31, 2012
			Gross		Gross			Gross			Estimated
			Amortized		Unrealized			Unrealized			Fair Value
			Costs		Gains			Losses
	Government and agency securities		$	1,312,876	$	985		$	(45	)	$	1,313,816
	Corporate debt securities, commercial paper, and bank certificates of deposit			2,039,809		1,597			(622	)		2,040,784
	Corporate equity securities			230		—			(33	)		197
	Alibaba Group Preference Shares			816,261		—			—			816,261
	Total investments in available-for-sale securities		$	4,169,176	$	2,582		$	(700	)	$	4,171,058
			September 30, 2013
			Gross		Gross			Gross			Estimated
			Amortized		Unrealized			Unrealized			Fair Value
			Costs		Gains			Losses
	Government and agency securities		$	294,644	$	110		$	(180	)	$	294,574
	Corporate debt securities, commercial paper, and bank certificates of deposit			2,078,519		1,339			(1,924	)		2,077,934
	Corporate equity and other marketable securities			230		141			—			371
	Total investments in available-for-sale securities		$	2,373,393	$	1,590		$	(2,104	)	$	2,372,879
Schedule of Available for Sale Securities by Balance Sheet Location	'
			December 31,		September 30,
			2012		2013
	Reported as:
	Short-term marketable securities		$	1,516,175	$	987,870
	Long-term marketable securities			1,838,425		1,384,638
	Alibaba Group Preference Shares			816,261		—
	Other assets			197		371
	Total		$	4,171,058	$	2,372,879
Schedule of Available for Sale Securities by Contractual Maturities	'
	The contractual maturities of available-for-sale marketable securities were as follows (in thousands):
			December 31,		September 30,
			2012		2013
	Due within one year		$	1,516,175	$	987,870
	Due after one year through five years			1,838,425		1,384,638
	Total available-for-sale marketable securities		$	3,354,600	$	2,372,508
Investments in Unrealized Loss Position	'
	The following tables show all investments in an unrealized loss position for which an other-than-temporary impairment has not been recognized and the related gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):
			December 31, 2012
			Less than 12 Months					12 Months or Greater						Total
			Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
			Value		Loss			Value			Loss			Value		Loss
	Government and agency securities		$	165,025	$	(45	)	$	—		$	—		$	165,025	$	(45	)
	Corporate debt securities, commercial paper, and bank certificates of deposit			729,046		(622	)		—			—			729,046		(622	)
	Corporate equity securities			197		(33	)		—			—			197		(33	)
	Total investments in available-for-sale securities		$	894,268	$	(700	)	$	—		$	—		$	894,268	$	(700	)
			September 30, 2013
			Less than 12 Months					12 Months or Greater						Total
			Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
			Value		Loss			Value			Loss			Value		Loss
	Government and agency securities		$	110,362	$	(180	)	$	—		$	—		$	110,362	$	(180	)
	Corporate debt securities, commercial paper, and bank certificates of deposit			948,913		(1,924	)		—			—			948,913		(1,924	)
	Total investments in available-for-sale securities		$	1,059,275	$	(2,104	)	$	—		$	—		$	1,059,275	$	(2,104	)
Schedule of Fair Value of Financial Assets Measured on Recurring Basis	'
	The following table sets forth the financial assets and liabilities, measured at fair value, by level within the fair value hierarchy as of December 31, 2012 (in thousands):
			Fair Value Measurements at Reporting Date Using
	Assets		Level 1		Level 2			Level 3			Total
	Money market funds(1)		$	685,707	$	—		$	—		$	685,707
	Available-for-sale securities:
	Government and agency securities(1)			—		2,464,227			—			2,464,227
	Commercial paper and bank certificates of deposit(1)			—		892,769			—			892,769
	Corporate debt securities(1)			—		1,298,123			—			1,298,123
	Time deposits			—		84,555			—			84,555
	Alibaba Group Preference Shares			—		—			816,261			816,261
	Corporate equity securities(2)			197		—			—			197
	Foreign currency derivative contracts(3)			—		5,007			—			5,007
	Financial assets at fair value		$	685,904	$	4,744,681		$	816,261		$	6,246,846
	Liabilities
	Foreign currency derivative contracts(3)			—		(6,662	)		—			(6,662	)
	Total financial assets and liabilities at fair value		$	685,904	$	4,738,019		$	816,261		$	6,240,184
	The following table sets forth the financial assets and liabilities, measured at fair value, by level within the fair value hierarchy as of September 30, 2013 (in thousands):
			Fair Value Measurements at Reporting Date Using
	Assets		Level 1		Level 2			Total
	Money market funds(1)		$	76,782	$	—		$	76,782
	Available-for-sale securities:
	Government and agency securities(1)			—		322,377			322,377
	Commercial paper and bank certificates of deposit(1)			—		291,886			291,886
	Corporate debt securities(1)			—		1,786,048			1,786,048
	Time deposits			—		80,261			80,261
	Corporate equity and other marketable securities(2)			371		—			371
	Foreign currency derivative contracts(3)			—		418,044			418,044
	Financial assets at fair value		$	77,153	$	2,898,616		$	2,975,769
	Liabilities
	Foreign currency derivative contracts(3)			—		(10,865	)		(10,865	)
	Total financial assets and liabilities at fair value		$	77,153	$	2,887,751		$	2,964,904
	(1)	The money market funds, government and agency securities, commercial paper and bank certificates of deposit, and corporate debt securities are classified as part of either cash and cash equivalents or investments in marketable securities in the condensed consolidated balance sheets.
	(2)	The corporate equity securities are classified as part of the other long-term assets and other marketable securities are classified as investments in marketable securities in the condensed consolidated balance sheets.
	(3)	Foreign currency derivative contracts are classified as part of either other current assets or other current liabilities in the condensed consolidated balance sheets. The notional amounts of the foreign currency derivative contracts were $3.4 billion, including contracts designated as net investment hedges of $3 billion, as of December 31, 2012, and $2.9 billion, including contracts designated as net investment hedges of $2.5 billion, as of September 30, 2013.

CONSOLIDATED_FINANCIAL_STATEME1

CONSOLIDATED FINANCIAL STATEMENT DETAILS (Tables)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income	'
	The components of accumulated other comprehensive income were as follows (in thousands):
		December 31,			September 30,
		2012			2013
	Unrealized gains on available-for-sale securities, net of tax	$	9,121		$	11,267
	Foreign currency translation, net of tax		562,128			249,503
	Accumulated other comprehensive income	$	571,249		$	260,770
Noncontrolling Interests	'
	Noncontrolling interests were as follows (in thousands):
		December 31,			September 30,
		2012			2013
	Beginning noncontrolling interests	$	40,280		$	45,403
	Net income attributable to noncontrolling interests		5,123			6,805
	Ending noncontrolling interests	$	45,403		$	52,208
Other Income Net	'
	Other income, net was as follows (in thousands):
		Three Months Ended					Nine Months Ended
		September 30,			September 30,		September 30,		September 30,
		2012			2013		2012		2013
	Interest, dividend, and investment income	$	6,402		$	5,362	$	15,682	$	53,214
	Gain related to sale of Alibaba Group Shares		4,603,322			—		4,603,322		—
	Other		(2,068	)		8		11,105		(7,166	)
	Total other income, net	$	4,607,656		$	5,370	$	4,630,109	$	46,048
Reclassifications Out of Accumulated Other Comprehensive Income	'
	Reclassifications out of accumulated other comprehensive income for the three months ended September 30, 2013 were as follows (in thousands):
		Amount			Affected Line Item in the
		Reclassified from			Statement of Income
		Accumulated
		Other
		Comprehensive
		Income
	Realized gains on cash flow hedges, net of tax	$	(106	)		Revenue
	Realized gains on available-for-sale securities, net of tax		(312	)		Other income, net
	Total reclassifications for the period	$	(418	)
	Reclassifications out of accumulated other comprehensive income for the nine months ended September 30, 2013 were as follows (in thousands):
		Amount			Affected Line Item in the
		Reclassified from			Statement of Income
		Accumulated
		Other
		Comprehensive
		Income
	Realized gains on cash flow hedges, net of tax	$	(83	)		Revenue
	Realized gains on available-for-sale securities, net of tax		(651	)		Other income, net
	Total reclassifications for the period	$	(734	)

ACQUISITIONS_Tables

ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2013
Allocation Of The Purchase Price Of Assets Acquired And Liabilities Assumed	'
	The preliminary allocation of the purchase price of the assets acquired and liabilities assumed based on their fair values was as follows (in thousands):
	Cash and marketable securities acquired	$	16,587
	Other tangible assets acquired		73,780
	Amortizable intangible assets:
	Developed technology		23,700
	Customer contracts and related relationships		182,400
	Trade name		56,500
	Goodwill		751,114
	Total assets acquired		1,104,081
	Liabilities assumed		(113,870	)
	Total	$	990,211

INTANGIBLE_ASSETS_NET_Tables

INTANGIBLE ASSETS, NET (Tables)	9 Months Ended
	Sep. 30, 2013
Intangible Assets Net	'
	The following table summarizes the Company’s intangible assets, net (in thousands):
			December 31, 2012		September 30, 2013
			Net		Gross Carrying		Accumulated			Net
					Amount		Amortization(*)
	Customer, affiliate, and advertiser related relationships		$	62,393	$	298,212	$	(80,605	)	$	217,607
	Developed technology and patents			71,634		269,920		(133,593	)		136,327
	Trade names, trademarks, and domain names			19,946		107,382		(33,965	)		73,417
	Total intangible assets, net		$	153,973	$	675,514	$	(248,163	)	$	427,351
	(*)	Cumulative foreign currency translation adjustments, reflecting movement in the currencies of the underlying entities increased total intangible assets by approximately $18 million as of September 30, 2013.

BASIC_AND_DILUTED_NET_INCOME_A1

BASIC AND DILUTED NET INCOME ATTRIBUTABLE TO YAHOO! INC. COMMON STOCKHOLDERS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2013
Computation of Basic and Diluted Net Income Per Share	'
	The following table sets forth the computation of basic and diluted net income per share (in thousands, except per share amounts):
		Three Months Ended						Nine Months Ended
		September 30,			September 30,			September 30,			September 30,
		2012			2013			2012			2013
	Basic:
	Numerator:
	Net income attributable to Yahoo! Inc.	$	3,160,238		$	296,656		$	3,673,212		$	1,018,091
	Less: Net income allocated to participating securities		(35	)		(6	)		(47	)		(24	)
	Net income attributable to Yahoo! Inc. common stockholders — basic	$	3,160,203		$	296,650		$	3,673,165		$	1,018,067
	Denominator:
	Weighted average common shares		1,186,046			1,024,289			1,205,050			1,065,949
	Net income attributable to Yahoo! Inc. common stockholders per share — basic	$	2.66		$	0.29		$	3.05		$	0.96
	Diluted:
	Numerator:
	Net income attributable to Yahoo! Inc.	$	3,160,238		$	296,656		$	3,673,212		$	1,018,091
	Less: Net income allocated to participating securities		(34	)		(6	)		(46	)		(24	)
	Less: Effect of dilutive securities issued by equity investees		(1,334	)		(5,040	)		(3,846	)		(10,778	)
	Net income attributable to Yahoo! Inc. common stockholders — diluted	$	3,158,870		$	291,610		$	3,669,320		$	1,007,289
	Denominator:
	Denominator for basic calculation		1,186,046			1,024,289			1,205,050			1,065,949
	Weighted average effect of Yahoo! Inc. dilutive securities:
	Restricted stock and restricted stock units		7,587			12,689			7,776			12,085
	Stock options and employee stock purchase plan		1,452			4,720			1,604			3,461
	Denominator for diluted calculation		1,195,085			1,041,698			1,214,430			1,081,495
	Net income attributable to Yahoo! Inc. common stockholders per share — diluted	$	2.64		$	0.28		$	3.02		$	0.93

INVESTMENTS_IN_EQUITY_INTEREST1

INVESTMENTS IN EQUITY INTERESTS (Tables)	9 Months Ended
	Sep. 30, 2013
Investments in Equity Interests	'
	The following table summarizes the Company’s investments in equity interests (dollars in thousands):
		December 31,		Percent			September 30,		Percent
		2012		Ownership			2013		Ownership
	Alibaba Group	$	276,389		24	%	$	807,736		24	%
	Yahoo Japan		2,555,717		35	%		2,300,854		35	%
	Other		8,051		24	%		11,860		20	%
	Total	$	2,840,157				$	3,120,450
Alibaba Group	'
Condensed Financial Information	'
	The following table presents Alibaba Group’s U.S. GAAP financial information, as derived from the Alibaba Group financial statements (in thousands):
		Three Months Ended					Nine Months Ended
		June 30,		June 30,			June 30,		June 30,
		2012		2013			2012		2013
	Operating data:
	Revenue	$	1,077,045	$	1,737,180		$	2,905,752	$	4,959,274
	Gross profit	$	739,914	$	1,287,807		$	1,967,290	$	3,653,739
	Income from operations	$	371,854	$	855,791		$	861,775	$	2,317,273
	Net income	$	292,928	$	716,991		$	781,701	$	2,046,505
	Net income attributable to Alibaba Group	$	273,043	$	706,708		$	730,438	$	2,017,557
		September 30,		June 30,
		2012		2013
	Balance sheet data:
	Current assets	$	4,062,823	$	6,841,126
	Long-term assets	$	3,204,144	$	5,284,556
	Current liabilities	$	2,624,656	$	4,078,438
	Long-term liabilities	$	4,705,347	$	5,269,175
	Convertible preferred shares	$	1,317,526	$	1,695,269
	Noncontrolling interests	$	65,907	$	87,613
Yahoo Japan	'
Condensed Financial Information	'
	The following tables present summarized financial information derived from Yahoo Japan’s consolidated financial statements, which are prepared on the basis of Japanese GAAP. The Company has made adjustments to the Yahoo Japan financial information to address differences between Japanese GAAP and U.S. GAAP that materially impact the summarized financial information below. Due to these adjustments, the Yahoo Japan summarized financial information presented below is not materially different than such information presented on the basis of U.S. GAAP.
		Three Months Ended					Nine Months Ended
		June 30,		June 30,			June 30,		June 30,
		2012		2013			2012		2013
		(in thousands)
	Operating data:
	Revenue	$	1,036,650	$	992,340		$	3,175,951	$	3,270,983
	Gross profit	$	877,116	$	818,441		$	2,693,956	$	2,733,506
	Income from operations	$	512,994	$	489,890		$	1,640,935	$	1,655,870
	Net income	$	315,949	$	364,612		$	966,646	$	1,056,323
	Net income attributable to Yahoo Japan	$	314,726	$	362,180		$	962,818	$	1,048,893
		September 30,		June 30,
		2012		2013
		(In thousands)
	Balance sheet data:
	Current assets	$	5,752,826	$	5,799,398
	Long-term assets	$	1,837,829	$	1,729,000
	Current liabilities	$	1,167,772	$	1,758,926
	Long-term liabilities	$	49,461	$	57,251
	Noncontrolling interests	$	31,034	$	58,247

DERIVATIVE_FINANCIAL_INSTRUMEN1

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Foreign Exchange Contracts	'
	Foreign currency forward contracts activity for the nine months ended September 30, 2013 was as follows (in millions):
			Beginning			Settlement		Gain (loss)			Gain (loss)			Gain		Ending fair
			fair value					recorded in			recorded in			(loss)		value
								other income,			other			recorded
								net			comprehensive			in
											income			revenue
	Derivatives designated as hedging instruments:
	Net investment hedges		$	3			—	$	—		$	409	(1)	$	—	$	412
	Cash flow hedges			—			—		—			1	(2)		—		1
	Derivatives not designated as hedging instruments:
	Balance sheet hedges			(5	)		6		(7	)		—			—		(6	)
	(1)	This amount does not reflect the tax impact of $154 million recorded during the nine months ended September 30, 2013. The $255 million after tax impact of the gain recorded under other comprehensive income was included in accumulated other comprehensive income on the Company’s condensed consolidated balance sheets.
	(2)	This amount does not reflect the tax impact of less than $1 million recorded during the nine months ended September 30, 2013. The less than $1 million after tax impact of the gain was included in accumulated other comprehensive income on the Company’s condensed consolidated balance sheets.

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	9 Months Ended
	Sep. 30, 2013
Lease Commitments	'
	A summary of gross and net lease commitments as of September 30, 2013 was as follows (in millions):
		Gross Operating			Sublease			Net Operating
		Lease			Income			Lease
		Commitments						Commitments
	Three months ending December 31, 2013	$	39		$	(3	)	$	36
	Years ending December 31,
	2014		132			(11	)		121
	2015		108			(7	)		101
	2016		72			(1	)		71
	2017		53			—			53
	2018		36			—			36
	Due after 5 years		108			—			108
	Total gross and net lease commitments	$	548		$	(22	)	$	526
Capital Lease Commitment	'
		Capital Lease
		Commitment
	Three months ending December 31, 2013	$	4
	Years ending December 31,
	2014		15
	2015		12
	2016		9
	2017		9
	2018		9
	Due after 5 years		4
	Gross lease commitment	$	62
	Less: interest		(16	)
	Net lease commitment included in capital lease and other long-term liabilities	$	46

STOCKHOLDERS_EQUITY_AND_EMPLOY1

STOCKHOLDERS' EQUITY AND EMPLOYEE BENEFITS (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Stock Based Compensation Activity	'
	Stock option activity under the Company’s Plans for the nine months ended September 30, 2013 is summarized as follows (in thousands, except per share amounts):
			Shares			Weighted Average
						Exercise Price Per
						Share
	Outstanding at December 31, 2012			38,092		$	21.42
	Options granted			42		$	26.93
	Options assumed			1,121		$	7.39
	Options exercised			(8,169	)	$	17.66
	Options expired			(3,250	)	$	29.73
	Options cancelled/forfeited			(1,013	)	$	15.2
	Outstanding at September 30, 2013			26,823		$	21.24
Schedule of Assumptions used to Calculate Fair Value of Options Granted and Shares Purchased in Employee Stock Purchase Plan	'
	The fair value of option grants is determined using the Black-Scholes option pricing model with the following weighted average assumptions:
			Stock Options						Purchase Plan (1)
			Three Months Ended						Three Months Ended
			September 30,			September 30,			September 30,			September 30,
			2012			2013			2012			2013
	Expected dividend yield			0	%		0	%		0	%		0	%
	Risk-free interest rate(2)			0.6	%		0.8	%		0.8	%		0.1	%
	Expected volatility			31.2	%		34.8	%		31.2	%		32	%
	Expected life (in years)(2)			4			3.17			1.86			0.25
			Stock Options						Purchase Plan (1)
			Nine Months Ended						Nine Months Ended
			September 30,			September 30,			September 30,			September 30,
			2012			2013			2012			2013
	Expected dividend yield			0	%		0	%		0	%		0	%
	Risk-free interest rate(2)			0.7	%		0.6	%		1.1	%		0.1	%
	Expected volatility			31.9	%		32.4	%		33.1	%		30.3	%
	Expected life (in years)(2)			4.03			3.47			1.46			0.25
	(1)	Assumptions for the Employee Stock Purchase Plan relate to the annual average of the enrollment periods. During the year ended December 31, 2012, enrollment was permitted in May and November of each year. Beginning in 2013, enrollment is permitted in February, May, August, and November of each year.
	(2)	Beginning in November 2012, the Employee Stock Purchase Plan was modified to consist of three-month offering periods.
Schedule of Restricted Stock Awards and Restricted Stock Units Activity	'
	Restricted stock and restricted stock unit activity under the Plans for the nine months ended September 30, 2013 is summarized as follows (in thousands, except per share amounts):
			Shares			Weighted Average
						Grant Date
						Fair Value
						Per Share
	Awarded and unvested at December 31, 2012(*)			33,801		$	17.63
	Granted(*)			28,140		$	23.34
	Assumed			2,364		$	26.24
	Vested			(11,759	)	$	15.05
	Forfeited			(5,805	)	$	17.33
	Awarded and unvested at September 30, 2013(*)			46,741		$	22.19
	(*)	Includes the maximum number of shares issuable under the Company’s performance-based restricted stock unit awards.

RESTRUCTURING_CHARGES_REVERSAL1

RESTRUCTURING CHARGES (REVERSALS), NET (Tables)	9 Months Ended
	Sep. 30, 2013
Restructuring Charges (Reversals), Net	'
	Restructuring charges (reversals), net was comprised of the following (in thousands):
		Three Months Ended September 30, 2012												Nine Months Ended September 30, 2012
		Restructuring			Q2’12			Q4’12			Total			Restructuring			Q2’12			Q4’12			Total
		Plans Prior			Restructuring			Korea						Plans Prior			Restructuring			Korea
		to			Plan			Business						to			Plan			Business
		2012						Closure						2012						Closure
	Employee severance pay and related costs	$	(44	)	$	11,511		$	—		$	11,467		$	3,617		$	102,577		$	—		$	106,194
	Non-cancelable lease, contract terminations, and other charges		2,104			9,332			—			11,436			6,360			9,949			—			16,309
	Other non-cash charges		—			1,824			—			1,824			—			40,462			—			40,462
	Sub-total before reversal of stock-based compensation expense		2,060			22,667			—			24,727			9,977			152,988			—			162,965
	Reversal of stock-based compensation expense for forfeitures		—			—			—			—			—			(3,429	)		—			(3,429	)
	Restructuring charges, net	$	2,060		$	22,667		$	—		$	24,727		$	9,977		$	149,559		$	—		$	159,536
		Three Months Ended September 30, 2013												Nine Months Ended September 30, 2013
		Restructuring			Q2’12			Q4’12			Total			Restructuring			Q2’12			Q4’12			Total
		Plans Prior			Restructuring			Korea						Plans Prior			Restructuring			Korea
		to			Plan			Business						to			Plan			Business
		2012						Closure						2012						Closure
	Employee severance pay and related costs	$	(20	)	$	(2,807	)	$	—		$	(2,827	)	$	(459	)	$	(15,784	)	$	(103	)	$	(16,346	)
	Non-cancelable lease, contract terminations, and other charges		2,217			33			1			2,251			11,652			131			(44	)		11,739
	Other non-cash charges		—			—			—			—			—			—			547			547
	Restructuring charges (reversals), net	$	2,197		$	(2,774	)	$	1		$	(576	)	$	11,193		$	(15,653	)	$	400		$	(4,060	)
Restructuring Accrual Activity	'
	The Company’s restructuring accrual activity for the nine months ended September 30, 2013 is summarized as follows (in thousands):
		Restructuring			Q2’12			Q4’12			Total
		Plans Prior to			Restructuring			Korea Business
		2012			Plan			Closure
	Balance as of January 1, 2013	$	27,716		$	35,049		$	10,102		$	72,867
	Employee severance pay and related costs		28			6,271			443			6,742
	Non-cancelable lease, contract termination, and other charges		12,127			131			1,227			13,485
	Other non-cash charges		—			—			547			547
	Changes in estimates and reversals of previous charges		(962	)		(22,055	)		(1,817	)		(24,834	)
	Restructuring charges (reversals), net for the nine months ended September 30, 2013	$	11,193		$	(15,653	)	$	400		$	(4,060	)
	Cash paid		(13,424	)		(15,358	)		(9,045	)		(37,827	)
	Other non-cash charges		—			—			(547	)		(547	)
	Foreign currency		142			(250	)		(171	)		(279	)
	Balance as of September 30, 2013	$	25,627		$	3,788		$	739		$	30,154
Restructuring Accruals by Segment	'
	Restructuring accruals by segment consisted of the following (in thousands):
		December 31,			September 30,
		2012			2013
	Americas	$	42,689		$	20,190
	EMEA		18,144			8,851
	Asia Pacific		12,034			1,113
	Total restructuring accruals	$	72,867		$	30,154

SEGMENTS_Tables

SEGMENTS (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Information	'
	The following tables present summarized information by segment (in thousands):
			Three Months Ended					Nine Months Ended
			September 30,		September 30,			September 30,		September 30,
			2012		2013			2012		2013
	Revenue by segment:
	Americas		$	843,731	$	850,935		$	2,501,515	$	2,521,667
	EMEA			96,473		89,156			358,534		281,367
	Asia Pacific			261,528		198,882			780,710		611,551
	Total Revenue		$	1,201,732	$	1,138,973		$	3,640,759	$	3,414,585
	TAC by segment:
	Americas		$	41,289	$	36,435		$	130,154	$	111,077
	EMEA			17,399		9,929			97,248		32,837
	Asia Pacific			54,141		12,100			166,543		44,934
	Total TAC		$	112,829	$	58,464		$	393,945	$	188,848
	Revenue ex-TAC by segment:
	Americas		$	802,442	$	814,500		$	2,371,361	$	2,410,590
	EMEA			79,074		79,227			261,286		248,530
	Asia Pacific			207,387		186,782			614,167		566,617
	Total Revenue ex-TAC		$	1,088,903	$	1,080,509		$	3,246,814	$	3,225,737
	Direct costs by segment(1):
	Americas			189,345		171,285			550,080		513,677
	EMEA			39,167		39,922			120,665		119,766
	Asia Pacific			56,329		47,583			164,068		152,264
	Global operating costs(2)(3)			396,269		490,594			1,228,686		1,354,118
	Depreciation and amortization			169,511		158,216			480,498		480,797
	Stock-based compensation expense			61,366		80,726			166,903		193,467
	Restructuring charges (reversals), net			24,727		(576	)		159,536		(4,060	)
	Income from operations		$	152,189	$	92,759		$	376,378	$	415,708
	(1)	Direct costs for each segment include cost of revenue—other as well as other operating expenses that are directly attributable to the segment such as employee compensation expense (excluding stock-based compensation expense), local sales and marketing expenses, and facilities expenses.
	(2)	Global operating costs include product development, service engineering and operations, general and administrative, and other corporate expenses that are managed on a global basis and that are not directly attributable to any segment.
	(3)	The net cost reimbursements from Microsoft pursuant to the Search Agreement are primarily included in global operating costs.
Capital Expenditures by Segment	'
			Three Months Ended					Nine Months Ended
			September 30,		September 30,			September 30,		September 30,
			2012		2013			2012		2013
	Capital expenditures, net:
	Americas		$	122,812	$	70,044		$	302,139	$	210,521
	EMEA			9,238		2,817			22,599		8,481
	Asia Pacific			7,815		4,792			31,049		10,308
	Total capital expenditures, net		$	139,865	$	77,653		$	355,787	$	229,310
Property and Equipment Net	'
			December 31,		September 30,
			2012		2013
	Property and equipment, net:
	Americas:
	U.S		$	1,483,225	$	1,383,769
	Other			1,869		1,428
	Total Americas		$	1,485,094	$	1,385,197
	EMEA			59,416		48,183
	Asia Pacific			141,335		102,982
	Total property and equipment, net		$	1,685,845	$	1,536,362
Enterprise Wide Disclosures Revenues for Groups of Similar Services	'
	The following table presents revenue for groups of similar services (in thousands):
			Three Months Ended					Nine Months Ended
			September 30,		September 30,			September 30,		September 30,
			2012		2013			2012		2013
	Display		$	506,002	$	469,932		$	1,552,191	$	1,396,745
	Search			472,537		435,192			1,403,903		1,278,081
	Other			223,193		233,849			684,665		739,759
	Total revenue		$	1,201,732	$	1,138,973		$	3,640,759	$	3,414,585
			Three Months Ended					Nine Months Ended
			September 30,		September 30,			September 30,		September 30,
			2012		2013			2012		2013
	Revenue:
	U.S.		$	800,984	$	812,048		$	2,379,955	$	2,401,527
	International			400,748		326,925			1,260,804		1,013,058
	Total revenue		$	1,201,732	$	1,138,973		$	3,640,759	$	3,414,585

Investments_in_Available_for_S

Investments in Available for Sale Securities (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Gross Amortized Costs	$2,373,393	$4,169,176
Gross Unrealized Gains	1,590	2,582
Gross Unrealized Losses	-2,104	-700
Estimated Fair Value, Total investments in available-for-sale securities	2,372,879	4,171,058
Government and agency securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Gross Amortized Costs	294,644	1,312,876
Gross Unrealized Gains	110	985
Gross Unrealized Losses	-180	-45
Estimated Fair Value, Total investments in available-for-sale securities	294,574	1,313,816
Corporate Debt Securities, Commercial Paper, And Bank Certificates Of Deposit	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Gross Amortized Costs	2,078,519	2,039,809
Gross Unrealized Gains	1,339	1,597
Gross Unrealized Losses	-1,924	-622
Estimated Fair Value, Total investments in available-for-sale securities	2,077,934	2,040,784
Corporate Equity Securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Gross Amortized Costs	'	230
Gross Unrealized Losses	'	-33
Estimated Fair Value, Total investments in available-for-sale securities	'	197
Corporate Equity And Other Marketable Securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Gross Amortized Costs	230	'
Gross Unrealized Gains	141	'
Estimated Fair Value, Total investments in available-for-sale securities	371	'
Alibaba Group | Preference Shares	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Gross Amortized Costs	'	816,261
Estimated Fair Value, Total investments in available-for-sale securities	'	$816,261

Available_for_Sale_Securities_

Available for Sale Securities by Balance Sheet Location (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Short-term marketable securities	$987,870	$1,516,175
Long-term marketable securities	1,384,638	1,838,425
Other assets	371	197
Total	2,372,879	4,171,058
Redeemable Preferred Stock	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Alibaba Group Preference Shares	'	$816,261

Available_for_Sale_Securities_1

Available for Sale Securities by Contractual Maturities (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments Classified by Contractual Maturity Date [Line Items]	'	'
Due within one year	$987,870	$1,516,175
Due after one year through five years	1,384,638	1,838,425
Total available-for-sale marketable securities	$2,372,508	$3,354,600

Investments_in_Unrealized_Loss

Investments in Unrealized Loss Position (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	$1,059,275	$894,268
Less than 12 Months, Unrealized Loss	-2,104	-700
12 Months or Greater, Fair Value	'	'
12 Months or Greater, Unrealized Loss	'	'
Total, Fair Value	1,059,275	894,268
Total, Unrealized Loss	-2,104	-700
Government and agency securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	110,362	165,025
Less than 12 Months, Unrealized Loss	-180	-45
12 Months or Greater, Fair Value	'	'
12 Months or Greater, Unrealized Loss	'	'
Total, Fair Value	110,362	165,025
Total, Unrealized Loss	-180	-45
Corporate Debt Securities, Commercial Paper, And Bank Certificates Of Deposit	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	948,913	729,046
Less than 12 Months, Unrealized Loss	-1,924	-622
12 Months or Greater, Fair Value	'	'
12 Months or Greater, Unrealized Loss	'	'
Total, Fair Value	948,913	729,046
Total, Unrealized Loss	-1,924	-622
Corporate Equity Securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Less than 12 Months, Fair Value	'	197
Less than 12 Months, Unrealized Loss	'	-33
12 Months or Greater, Fair Value	'	'
12 Months or Greater, Unrealized Loss	'	'
Total, Fair Value	'	197
Total, Unrealized Loss	'	($33)

Investment_and_Fair_Value_Meas

Investment and Fair Value Measurements - Additional Information (Detail) (USD $)	9 Months Ended		1 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	16-May-13	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2012
			Alibaba Group	Alibaba Group	Alibaba Group	Alibaba Group
					Prepaid Expense And Other Assets Current	Redeemable Preferred Stock
Cash And Cash Equivalents And Investments [Line Items]	'	'	'	'	'	'
Fair Value Amount	'	'	'	'	'	$822,000,000
Accrued dividend income	'	'	'	16,000,000	6,000,000	'
Proceeds related to the redemption of Alibaba Group Preference Shares and dividends	'	'	846,000,000	'	'	'
Proceeds related to the redemption of Alibaba Group Preference Shares	800,000,000	'	800,000,000	'	'	'
Cash dividend received related to Preference Shares	'	'	46,000,000	'	'	'
Cash deposited with commercial banks	$658,000,000	$597,000,000	'	'	'	'

Fair_Value_of_Financial_Assets

Fair Value of Financial Assets (Detail) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value Measurements At Reporting Date Using Level 1	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Financial assets at fair value	$77,153		$685,904
Total assets and liabilities at fair value	77,153		685,904
Fair Value Measurements At Reporting Date Using Level 1 | Money Market Funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Money market funds	76,782	[1]	685,707	[1]
Fair Value Measurements At Reporting Date Using Level 1 | Corporate Equity Securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	'		197	[2]
Fair Value Measurements At Reporting Date Using Level 1 | Corporate Equity And Other Marketable Securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	371	[2]	'
Fair Value Measurements At Reporting Date Using Level 2	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Financial assets at fair value	2,898,616		4,744,681
Total assets and liabilities at fair value	2,887,751		4,738,019
Fair Value Measurements At Reporting Date Using Level 2 | Government and agency securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	322,377	[1]	2,464,227	[1]
Fair Value Measurements At Reporting Date Using Level 2 | Commercial Paper And Bank Certificates Of Deposit	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	291,886	[1]	892,769	[1]
Fair Value Measurements At Reporting Date Using Level 2 | Corporate Debt Securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	1,786,048	[1]	1,298,123	[1]
Fair Value Measurements At Reporting Date Using Level 2 | Bank Time Deposits	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	80,261		84,555
Fair Value Measurements At Reporting Date Using Level 2 | Foreign currency derivative	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Foreign currency derivative contracts	418,044	[3]	5,007	[3]
Foreign currency derivative contracts	-10,865	[3]	-6,662	[3]
Fair Value, Inputs, Level 3	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Financial assets at fair value	'		816,261
Total assets and liabilities at fair value	'		816,261
Fair Value, Inputs, Level 3 | Preference Shares | Alibaba Group	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	'		816,261
Fair Value Measurements At Reporting Date Using Total	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Financial assets at fair value	2,975,769		6,246,846
Total assets and liabilities at fair value	2,964,904		6,240,184
Fair Value Measurements At Reporting Date Using Total | Money Market Funds	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Money market funds	76,782	[1]	685,707	[1]
Fair Value Measurements At Reporting Date Using Total | Government and agency securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	322,377	[1]	2,464,227	[1]
Fair Value Measurements At Reporting Date Using Total | Commercial Paper And Bank Certificates Of Deposit	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	291,886	[1]	892,769	[1]
Fair Value Measurements At Reporting Date Using Total | Corporate Debt Securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	1,786,048	[1]	1,298,123	[1]
Fair Value Measurements At Reporting Date Using Total | Bank Time Deposits	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	80,261		84,555
Fair Value Measurements At Reporting Date Using Total | Preference Shares | Alibaba Group	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	'		816,261
Fair Value Measurements At Reporting Date Using Total | Corporate Equity Securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	'		197	[2]
Fair Value Measurements At Reporting Date Using Total | Foreign currency derivative	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Foreign currency derivative contracts	418,044	[3]	5,007	[3]
Foreign currency derivative contracts	-10,865	[3]	-6,662	[3]
Fair Value Measurements At Reporting Date Using Total | Corporate Equity And Other Marketable Securities	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Available-for-sale securities	$371	[2]	'
[1]	The money market funds, government and agency securities, commercial paper and bank certificates of deposit, and corporate debt securities are classified as part of either cash and cash equivalents or investments in marketable securities in the condensed consolidated balance sheets.
[2]	The corporate equity securities are classified as part of the other long-term assets and other marketable securities are classified as investments in marketable securities in the condensed consolidated balance sheets.
[3]	Foreign currency derivative contracts are classified as part of either other current assets or other current liabilities in the condensed consolidated balance sheets. The notional amounts of the foreign currency derivative contracts were $3.4 billion, including contracts designated as net investment hedges of $3 billion, as of December 31, 2012, and $2.9 billion, including contracts designated as net investment hedges of $2.5 billion, as of September 30, 2013.

Fair_Value_of_Financial_Assets1

Fair Value of Financial Assets (Parenthetical) (Detail) (Foreign currency derivative, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Foreign currency derivative contract, notional amount	$2,900	$3,400
Net Investment Hedging	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Foreign currency derivative contract, notional amount	$2,500	$3,000

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Unrealized gains on available-for-sale securities, net of tax	$11,267	$9,121
Foreign currency translation, net of tax	249,503	562,128
Accumulated other comprehensive income	$260,770	$571,249

Noncontrolling_Interests_Detai

Noncontrolling Interests (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Noncontrolling Interest [Line Items]	'	'	'	'	'
Beginning noncontrolling interests	'	'	$45,403	$40,280	$40,280
Net income attributable to noncontrolling interests	2,338	778	6,805	3,738	5,123
Ending noncontrolling interests	$52,208	'	$52,208	'	$45,403

Other_Income_Expense_Net_Detai

Other Income Expense Net (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Components of Other Income (Expense) [Line Items]	'	'	'	'
Interest, dividend, and investment income	$5,362	$6,402	$53,214	$15,682
Gain related to sale of Alibaba Group Shares	'	4,603,322	'	4,603,322
Other	8	-2,068	-7,166	11,105
Total other income, net	$5,370	$4,607,656	$46,048	$4,630,109

Recovered_Sheet1

Consolidated Financial Statement Details - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2012	Sep. 30, 2012
Financial Statement Details [Line Items]	'	'
Gain related to sale of Alibaba Group Shares	$4,603,322	$4,603,322

Reclassifications_Out_of_Accum

Reclassifications Out of Accumulated Other Comprehensive Income (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Revenue	$1,138,973	$1,201,732	$3,414,585	$3,640,759
Other income, net	5,370	4,607,656	46,048	4,630,109
Net Income Attributable to Yahoo! Inc.	296,656	3,160,238	1,018,091	3,673,212
Reclassification out of Accumulated Other Comprehensive Income	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Net Income Attributable to Yahoo! Inc.	-418	'	-734	'
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Revenue	-106	'	-83	'
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Realized Investment Gains (Losses)	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Other income, net	($312)	'	($651)	'

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			1 Months Ended				9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Jun. 19, 2013	Jun. 19, 2013	Jun. 19, 2013	Jun. 19, 2013	Sep. 30, 2013
						Tumblr	Tumblr	Tumblr	Tumblr	Other Acquisitions
							Maximum	Unvested Stock Options and Restricted Stock Units	Common Stock	Entity
Business Acquisition [Line Items]	'	'	'	'	'	'	'	'	'	'
Business combination, total purchase price	'	'	'	'	'	$990,000,000	'	'	'	$218,000,000
Stock-based compensation expense	80,726,000	61,366,000	193,467,000	166,903,000	'	70,000,000	'	'	'	'
Period for recognizing stock-based compensation contingently issuable in acquisition	'	'	'	'	'	'4 years	'	'	'	'
Stock based compensation contingently issuable	'	'	'	'	'	'	'	29,000,000	41,000,000	'
Contingent cash consideration to be paid to Tumblr's founder	'	'	'	'	'	40,000,000	'	'	'	'
Contingent cash consideration, payment period	'	'	'	'	'	'4 years	'	'	'	'
Useful life of amortizable intangible assets	'	'	'	'	'	'	'6 years	'	'	'
Weighted average useful life of amortizable intangible assets	'	'	'	'	'	'6 years	'	'	'	'
Goodwill	4,704,859,000	'	4,704,859,000	'	3,826,749,000	751,114,000	'	'	'	148,000,000
Business combination, number of entities acquired	'	'	'	'	'	'	'	'	'	17
Business combination, cash acquired	'	'	'	'	'	'	'	'	'	2,000,000
Business combination, cash consideration paid net of cash acquired	'	'	1,187,229,000	'	'	'	'	'	'	216,000,000
Business combination, amortizable intangible assets	'	'	'	'	'	'	'	'	'	77,000,000
Business combination, other tangible assets	'	'	'	'	'	73,780,000	'	'	'	23,000,000
Business combination, net assumed liabilities	'	'	'	'	'	$113,870,000	'	'	'	$32,000,000

Allocation_of_Purchase_Price_o

Allocation of Purchase Price of Assets Acquired And Liabilities Assumed Based on their Fair Values (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Jun. 19, 2013	Jun. 19, 2013	Jun. 19, 2013	Jun. 19, 2013
In Thousands, unless otherwise specified			Tumblr	Developed Technology	Customer Contracts and Related Relationships	Trade Name
				Tumblr	Tumblr	Tumblr
Business Acquisition [Line Items]	'	'	'	'	'	'
Cash and marketable securities acquired	'	'	$16,587	'	'	'
Other tangible assets acquired	'	'	73,780	'	'	'
Amortizable intangible assets	'	'	'	23,700	182,400	56,500
Goodwill	4,704,859	3,826,749	751,114	'	'	'
Total assets acquired	'	'	1,104,081	'	'	'
Liabilities assumed	'	'	-113,870	'	'	'
Total	'	'	$990,211	'	'	'

Goodwill_Additional_Informatio

Goodwill - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Goodwill [Line Items]	'	'
Goodwill	$4,704,859,000	$3,826,749,000
Increase in carrying amount of goodwill	878,000,000	'
Addition related to acquisitions	899,000,000	'
Foreign currency translation adjustments	-21,000,000	'
Americas	'	'
Goodwill [Line Items]	'	'
Goodwill	3,800,000,000	2,900,000,000
EMEA	'	'
Goodwill [Line Items]	'	'
Goodwill	600,000,000	600,000,000
Asia Pacific	'	'
Goodwill [Line Items]	'	'
Goodwill	$300,000,000	$300,000,000

Intangible_Assets_Net_Detail

Intangible Assets Net (Detail) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]	'		'
Net	$427,351		$153,973
Gross Carrying Amount	675,514		'
Accumulated Amortization	-248,163	[1]	'
Customer, Affiliate And Advertiser Related Relationships	'		'
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]	'		'
Net	217,607		62,393
Gross Carrying Amount	298,212		'
Accumulated Amortization	-80,605	[1]	'
Developed Technology And Patents	'		'
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]	'		'
Net	136,327		71,634
Gross Carrying Amount	269,920		'
Accumulated Amortization	-133,593	[1]	'
Trade Names, Trademarks, And Domain Names	'		'
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]	'		'
Net	73,417		19,946
Gross Carrying Amount	107,382		'
Accumulated Amortization	($33,965)	[1]	'
[1]	Cumulative foreign currency translation adjustments, reflecting movement in the currencies of the underlying entities increased total intangible assets by approximately $18 million as of September 30, 2013.

Intangible_Assets_Net_Parenthe

Intangible Assets Net (Parenthetical) (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]	'
Cumulative foreign currency translation adjustments	$18

Intangible_Assets_Net_Addition

Intangible Assets Net - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]	'	'	'	'
Amortization expense for intangible assets	$31	$24	$68	$84
Amortization expense in cost of revenue - other	16	16	38	56
Estimated amortization expense three months ending December 31, 2013	27	'	27	'
Estimated amortization expense 2014	101	'	101	'
Estimated amortization expense 2015	80	'	80	'
Estimated amortization expense 2016	55	'	55	'
Estimated amortization expense thereafter	$148	'	$148	'

Recovered_Sheet2

Basic and Diluted Net Income Attributable to Yahoo Inc. Common Stockholders Per Share - Additional Information (Detail)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]	'	'	'	'
Anti-dilutive securities excluded from computation of earnings per share	4	37	12	44

Computation_of_Basic_and_Dilut

Computation of Basic and Diluted Net Income per Share (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]	'	'	'	'
Net Income Attributable to Yahoo! Inc.	$296,656	$3,160,238	$1,018,091	$3,673,212
Less: Net income allocated to participating securities	-6	-35	-24	-47
Net income attributable to Yahoo! Inc. common stockholders - basic	296,650	3,160,203	1,018,067	3,673,165
Weighted average common shares	1,024,289	1,186,046	1,065,949	1,205,050
Net income attributable to Yahoo! Inc. common stockholders per share - basic	$0.29	$2.66	$0.96	$3.05
Net income attributable to Yahoo! Inc.	296,656	3,160,238	1,018,091	3,673,212
Less: Net income allocated to participating securities	-6	-34	-24	-46
Less: Effect of dilutive securities issued by equity investees	-5,040	-1,334	-10,778	-3,846
Net income attributable to Yahoo! Inc. common stockholders - diluted	$291,610	$3,158,870	$1,007,289	$3,669,320
Denominator for basic calculation	1,024,289	1,186,046	1,065,949	1,205,050
Restricted stock and restricted stock units	12,689	7,587	12,085	7,776
Stock options and employee stock purchase plan	4,720	1,452	3,461	1,604
Denominator for diluted calculation	1,041,698	1,195,085	1,081,495	1,214,430
Net income attributable to Yahoo! Inc. common stockholders per share - diluted	$0.28	$2.64	$0.93	$3.02

Recovered_Sheet3

Investments in Equity Interests (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Equity Method Investments [Line Items]	'	'
Investment in equity interests	$3,120,450	$2,840,157
Alibaba Group	'	'
Schedule of Equity Method Investments [Line Items]	'	'
Investment in equity interests	807,736	276,389
Percent ownership of common stock as of balance sheet date	24.00%	24.00%
Yahoo Japan	'	'
Schedule of Equity Method Investments [Line Items]	'	'
Investment in equity interests	2,300,854	2,555,717
Percent ownership of common stock as of balance sheet date	35.00%	35.00%
Other	'	'
Schedule of Equity Method Investments [Line Items]	'	'
Investment in equity interests	$11,860	$8,051
Percent ownership of common stock as of balance sheet date	20.00%	24.00%

Recovered_Sheet4

Investments in Equity Interests - Additional Information (Detail) (USD $)

3 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Share data in Millions, except Per Share data, unless otherwise specified

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

16-May-13

Sep. 18, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Oct. 14, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Alibaba Group

Yahoo Japan

Yahoo Japan

Yahoo Japan

Yahoo Japan

Yahoo Japan

Prior to amendment on the Repurchase Closing Date

Prior to amendment on the Repurchase Closing Date

Prior to amendment on the Repurchase Closing Date

Prior to amendment on the Repurchase Closing Date

Subsequent Event

Maximum

Minimum

Schedule of Equity Method Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sale of investments in equity interests, shares

'

'

'

'

523

'

'

'

523

'

'

'

'

'

'

'

'

'

'

'

'

Shares of Alibaba Group owned by Yahoo

'

'

'

'

1,047

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sale of investments in equity interests, price per share

'

'

'

'

$13.54

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sale of investments in equity interests, total consideration received

'

'

'

'

$7,100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sale of investments in equity interests, cash received

'

'

6,247,728,000

'

6,300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Sale of investments in equity interests, value of preference shares

'

'

'

'

800,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain related to sale of Alibaba shares

4,603,322,000

'

4,603,322,000

'

'

'

'

'

4,600,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Expected rate of annual dividend on the issuance of preference shares by Alibaba Group

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10.00%

'

'

'

'

'

'

Expected rate of annual dividend payable in cash of preference shares by Alibaba Group

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.00%

'

'

'

'

'

Proceeds related to the redemption of Alibaba Group Preference Shares and dividends

'

'

'

846,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds related to the redemption of Alibaba Group Preference Shares

'

800,000,000

'

800,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash dividend received related to Preference Shares

'

'

'

46,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum number of shares required to sell in connection with Qualified IPO

'

'

'

'

'

261.5

'

261.5

'

'

'

'

'

208

'

'

'

'

'

'

'

Future Royalty Payment received

'

'

'

'

'

550,000,000

'

550,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Technology and Intellectual Property License Agreement, remaining term

'

'

'

'

'

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

'

'

'

Royalty received

'

'

'

'

'

34,000,000

5,000,000

103,000,000

'

27,000,000

19,000,000

83,000,000

51,000,000

'

'

'

'

'

'

'

'

Fair value of the company's ownership interest in the common stock of Yahoo Japan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11,400,000,000

'

11,400,000,000

'

'

Cash dividends received

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

77,000,000

84,000,000

'

Revenue received through commercial arrangements with Yahoo Japan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

65,000,000

75,000,000

199,000,000

211,000,000

'

Net receivables balance from Yahoo Japan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$42,000,000

'

$42,000,000

'

$43,000,000

Alibaba_Group_Condensed_Financ

Alibaba Group Condensed Financial Information Operating Data (Detail) (Alibaba Group, USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Alibaba Group	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'
Revenue	$1,737,180	$1,077,045	$4,959,274	$2,905,752
Gross profit	1,287,807	739,914	3,653,739	1,967,290
Income from operations	855,791	371,854	2,317,273	861,775
Net income	716,991	292,928	2,046,505	781,701
Net income attributable to Alibaba Group	$706,708	$273,043	$2,017,557	$730,438

Alibaba_Group_Condensed_Financ1

Alibaba Group Condensed Financial Information Balance Sheet Data (Detail) (Alibaba Group, USD $)	Jun. 30, 2013	Sep. 30, 2012
In Thousands, unless otherwise specified
Alibaba Group	'	'
Schedule of Equity Method Investments [Line Items]	'	'
Current assets	$6,841,126	$4,062,823
Long-term assets	5,284,556	3,204,144
Current liabilities	4,078,438	2,624,656
Long-term liabilities	5,269,175	4,705,347
Convertible preferred shares	1,695,269	1,317,526
Noncontrolling interests	$87,613	$65,907

Yahoo_Japan_Condensed_Financia

Yahoo Japan Condensed Financial Information Operating Data (Detail) (Yahoo Japan, USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Yahoo Japan	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'
Revenue	$992,340	$1,036,650	$3,270,983	$3,175,951
Gross profit	818,441	877,116	2,733,506	2,693,956
Income from operations	489,890	512,994	1,655,870	1,640,935
Net income	364,612	315,949	1,056,323	966,646
Net income attributable to Yahoo Japan	$362,180	$314,726	$1,048,893	$962,818

Yahoo_Japan_Condensed_Financia1

Yahoo Japan Condensed Financial Information Balance Sheet Data (Detail) (Yahoo Japan, USD $)	Jun. 30, 2013	Sep. 30, 2012
In Thousands, unless otherwise specified
Yahoo Japan	'	'
Schedule of Equity Method Investments [Line Items]	'	'
Current assets	$5,799,398	$5,752,826
Long-term assets	1,729,000	1,837,829
Current liabilities	1,758,926	1,167,772
Long-term liabilities	57,251	49,461
Noncontrolling interests	$58,247	$31,034

Recovered_Sheet5

Derivative Financial Instruments - Additional Information (Detail) (USD $)

3 Months Ended

9 Months Ended

9 Months Ended

12 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

31-May-13

Sep. 30, 2013

Sep. 30, 2013

Cash Flow Hedge

Cash Flow Hedge

Foreign currency derivative

Foreign currency derivative

Foreign currency derivative

Foreign currency derivative

Foreign currency derivative

Foreign currency derivative

Foreign currency derivative

Foreign currency derivative

Foreign currency derivative

Foreign Exchange Contract Designed As Cash Flow Hedges

Foreign Exchange Contract Designed As Cash Flow Hedges

Foreign Exchange Contract Designed As Cash Flow Hedges

Maximum

Maximum

Net Investment Hedging

Net Investment Hedging

Balance Sheet Hedge

Balance Sheet Hedge

Balance Sheet Hedge

Balance Sheet Hedge

Balance Sheet Hedge

Maximum

Derivative [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Forward contracts maturity Period

'

'

'

'

'9 months

'

'

'

'

'

'

'

'

'

Forward contracts maturity Period

'

'

'

'

'15 months

'

'

'

'

'

'

'

'

'

Foreign currency derivative contract, notional amount

'

'

$2,900,000,000

$3,400,000,000

$2,500,000,000

$3,000,000,000

$398,000,000

'

$398,000,000

'

$356,000,000

'

$82,000,000

'

Fair value of the foreign currency forward contract asset

'

'

'

'

416,000,000

3,000,000

'

'

'

'

'

'

'

1,000,000

Fair value of the foreign currency forward contract liability

'

'

'

'

4,000,000

'

6,000,000

'

6,000,000

'

5,000,000

'

'

'

Gain (loss) on foreign currency forward contract

'

'

'

'

412,000,000

3,000,000

'

'

'

'

'

'

'

'

Foreign currency forward contracts designated as cash flow hedges maturities

'

'

'

'

'

'

'

'

'

'

'

31-Jan-14

'

'

Gain on foreign currency forward contracts

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

Gain (loss) on foreign currency forward contract

1,000,000

1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Gain (loss) on foreign currency forward contract

'

'

'

'

'

'

-11,000,000

13,000,000

-7,000,000

8,000,000

'

'

'

'

Cash received (paid) to settle foreign currency forward contracts

'

'

'

'

'

'

'

'

$6,000,000

'

'

'

'

'

Foreign_Currency_Forward_Contr

Foreign Currency Forward Contracts Activity (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013
Net Investment Hedging | Derivatives Designated as Hedging Instruments	'
Derivative [Line Items]	'
Beginning Fair Value	$3,000,000
Gain (loss) recorded in other comprehensive income, net	409,000,000	[1]
Gain (loss) recorded in revenue	'
Ending Fair Value	412,000,000
Cash Flow Hedge | Derivatives Designated as Hedging Instruments	'
Derivative [Line Items]	'
Gain (loss) recorded in other comprehensive income, net	1,000,000	[2]
Gain (loss) recorded in revenue	'
Ending Fair Value	1,000,000
Balance Sheet Hedge | Derivatives Not Designated as Hedging Instruments	'
Derivative [Line Items]	'
Settlement	6,000,000
Gain (loss) recorded in Other income, net	-7,000,000
Gain (loss) recorded in revenue	'
Beginning Fair Value	-5,000,000
Ending fair value	($6,000,000)
[1]	This amount does not reflect the tax impact of $154 million recorded during the nine months ended September 30, 2013. The $255 million after tax impact of the gain recorded under other comprehensive income was included in accumulated other comprehensive income on the Company's condensed consolidated balance sheets.
[2]	This amount does not reflect the tax impact of less than $1 million recorded during the nine months ended September 30, 2013. The less than $1 million after tax impact of the gain was included in accumulated other comprehensive income on the Company's condensed consolidated balance sheets.

Foreign_Currency_Forward_Contr1

Foreign Currency Forward Contracts Activity (Parenthetical) (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative [Line Items]	'	'	'	'
Net investment hedge CTA, net of tax	($57,003,000)	$28,009,000	($312,625,000)	($193,128,000)
Cash flow hedge CTA, net of tax	750,000	'	784,000	'
Net Investment Hedging | Derivatives Designated as Hedging Instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Net investment hedge CTA, tax	'	'	154,000,000	'
Net investment hedge CTA, net of tax	'	'	255,000,000	'
Maximum | Cash Flow Hedge | Derivatives Designated as Hedging Instruments	'	'	'	'
Derivative [Line Items]	'	'	'	'
Cash flow hedge CTA, tax	'	'	1,000,000	'
Cash flow hedge CTA, net of tax	'	'	$1,000,000	'

Credit_Agreement_Additional_In

Credit Agreement - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended	9 Months Ended
	Jul. 25, 2013	Sep. 30, 2013	Sep. 30, 2013
Line of Credit Facility [Line Items]	'	'	'
Unsecured revolving credit facility	'	$750,000,000	$750,000,000
Unsecured revolving credit facility expiration date	'	'	18-Oct-13
Unsecured revolving credit facility term, additional	'	'	'364 days
Unsecured revolving credit facility, additional commitment	'	250,000,000	250,000,000
Borrowing under credit agreement	$150,000,000	$150,000,000	$150,000,000
Eurodollar | Minimum	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Unsecured revolving credit facility, applicable margin on borrowing rate	'	1.25%	1.25%
Eurodollar | Maximum	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Unsecured revolving credit facility, applicable margin on borrowing rate	'	1.50%	1.50%
Base Rate | Minimum	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Unsecured revolving credit facility, applicable margin on borrowing rate	'	0.25%	0.25%
Base Rate | Maximum	'	'	'
Line of Credit Facility [Line Items]	'	'	'
Unsecured revolving credit facility, applicable margin on borrowing rate	'	0.50%	0.50%

Recovered_Sheet6

Commitments and Contingencies - Additional Information (Detail) (USD $)

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

9 Months Ended

Share data in Millions, unless otherwise specified

31-May-13

15-May-13

Nov. 30, 2011

Sep. 30, 2013

Dec. 31, 2011

Nov. 30, 2012

Nov. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jul. 25, 2013

Sep. 30, 2013

31-May-13

Sep. 30, 2013

LegalMatter

Damages Allegged, Loss of Profit

Non-Final Judgment

May 2012 Plan

Payable In 2013

Payable In 2014

Payable In 2015

Payable In 2016

Share repurchase from Third Point

Minimum

Minimum

Maximum

May 2012 Plan

Commitments and Contingencies Disclosure [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease periods (years)

'

'

'

'12 years

'

'

'

'

'

'

'

'

'

'

'

'

Lease expiration period

'

'

'

'

'

'

'

'

'

'

'

'

'

'2013

'

'2025

Lease periods

'12 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease commitment

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$125,000,000

'

Additional lease period

'5 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease monthly payments

1,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease monthly payment start period

'2015-07

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease monthly payment end period

'2025-06

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Affiliate commitments

'

'

'

33,000,000

'

'

'

'

22,000,000

9,000,000

1,000,000

1,000,000

'

'

'

'

Intellectual property arrangements through 2023

'

'

'

29,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Number of purported stockholder class action suits filed

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

Repurchases of common stock, shares

'

'

'

'

'

'

'

123

'

'

'

'

40

'

'

'

Alleged total damages

'

'

2,750,000,000

'

'

2,400,000,000

2,750,000,000

'

'

'

'

'

'

'

'

'

Counterclaim filed for payments of services rendered

'

2,600,000

'

'

2,600,000

'

2,600,000

'

'

'

'

'

'

'

'

'

Loss Contingency

'

$172,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Lease_Commitments_Detail

Lease Commitments (Detail) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Commitments and Contingencies [Line Items]	'
Three months ending December 31, 2013	($3)
Years ending December 31, 2014	-11
2015	-7
2016	-1
2017	'
2018	'
Due after 5 years	'
Total gross and net lease commitments	-22
Gross Operating Lease Commitments	'
Commitments and Contingencies [Line Items]	'
Three months ending December 31, 2013	39
Years ending December 31, 2014	132
2015	108
2016	72
2017	53
2018	36
Due after 5 years	108
Total gross and net lease commitments	548
Net Operating Lease Commitments	'
Commitments and Contingencies [Line Items]	'
Three months ending December 31, 2013	36
Years ending December 31, 2014	121
2015	101
2016	71
2017	53
2018	36
Due after 5 years	108
Total gross and net lease commitments	$526

Capital_Lease_Commitment_Detai

Capital Lease Commitment (Detail) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Schedule of Capital Lease Obligations [Line Items]	'
Three months ending December 31, 2013	$4
Years ending December 31, 2014	15
2015	12
2016	9
2017	9
2018	9
Due after 5 years	4
Gross lease commitment	62
Less: interest	-16
Net lease commitment included in capital lease and other long-term liabilities	$46

Recovered_Sheet7

Stockholders Equity and Employee Benefits - Additional Information (Detail) (USD $)

1 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

Jul. 25, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

31-May-12

Sep. 30, 2013

Jul. 25, 2013

Jul. 25, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

May 2012 Plan

May 2012 Plan

Share repurchase from Third Point

Share repurchase from Third Point

Performance Based Stock Options

Performance Based Stock Options

Performance Based Stock Options

Performance Based Stock Options

Performance Based Stock Options

Performance Based Stock Options

Performance Based Stock Options

Performance Based Restricted Stock Units

Performance Based Restricted Stock Units

Performance Based Restricted Stock Units

Performance Based Restricted Stock Units

Performance Based Restricted Stock Units

Performance Based Restricted Stock Units

Employee Stock Purchase Plan

Stock Options

Restricted Stock Awards And Units

Restricted Stock Awards And Units

May 2012 Plan

First Tranche

Second Tranche

Minimum

Maximum

Revenues ex -TAC

Operating Income

Free Cash Flow

Minimum

Maximum

Revenues ex -TAC

Operating Income

Free Cash Flow

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized stock-based compensation expense

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$5,000,000

$22,000,000

$542,000,000

'

Stock-based compensation, recognition period

'

'

'

'

'

'

'

'

'6 months

'12 months

'

'

'

'

'

'1 year

'

'

'

'

'

'7 months 6 days

'1 year 6 months

'2 years 4 months 24 days

'

Vested

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

11,800,000

8,800,000

Shares withheld to settle employees' minimum statutory obligation for applicable income and other employment taxes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,300,000

3,200,000

Payments made to taxing authorities for employees' tax obligations

'

'

106,177,000

48,097,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock awards vesting percentage for each performance period

'

'

'

'

'

'

'

'

'

'

0.00%

100.00%

'

'

'

'

0.00%

200.00%

'

'

'

'

'

'

'

Financial performance metrics for stock option awards

'

'

'

'

'

'

'

'

'

'

'

'

50.00%

30.00%

20.00%

'

'

'

'

'

'

'

'

'

'

Stock options grant date fair value

'

'

'

'

'

'

'

'

12,000,000

14,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Financial performance metrics for restricted stock units awards

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

60.00%

20.00%

20.00%

'

'

'

'

Restricted stock units grant date fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9,000,000

'

'

'

'

'

'

'

'

'

Treasury stock repurchase authorization value

'

'

'

'

5,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock repurchase program expiration date

'

'

'

'

'

'2015-06

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock repurchase, aggregate amount available

'

'

'

'

'

324,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchases of common stock, shares

'

'

'

'

'

123,000,000

'

40,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchases of common stock, value

'

'

'

'

'

3,100,000,000

1,164,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Average purchase price per share of common stock repurchased during the period

'

'

'

'

'

$25.41

$29.11

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit borrowings to fund repurchase transaction

$150,000,000

$150,000,000

$150,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stock_Option_Activity_Detail

Stock Option Activity (Detail) (USD $)	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Outstanding stock options, Beginning balance	38,092
Stock options granted during the period	42
Stock options assumed during the period	1,121
Stock options exercised during the period	-8,169
Stock options expired during the period	-3,250
Stock options cancelled/forfeited during the period	-1,013
Outstanding stock options, Ending balance	26,823
Weighted average exercise price of options outstanding, Beginning balance	$21.42
Weighted-average exercise price of shares granted during period	$26.93
Weighted-average exercise price of shares assumed during period	$7.39
Weighted-average exercise price of shares exercised during period	$17.66
Weighted-average exercise price of shares expired during period	$29.73
Weighted-average exercise price of shares cancelled/forfeited during period	$15.20
Weighted average exercise price of options outstanding, Ending balance	$21.24

Weighted_Average_Assumptions_U

Weighted Average Assumptions Used to Calculate Fair Value of Options Granted (Detail)	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Stock Options	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Expected dividend yield	0.00%		0.00%		0.00%		0.00%
Risk-free interest rate	0.80%	[1]	0.60%	[1]	0.60%	[1]	0.70%	[1]
Expected volatility	34.80%		31.20%		32.40%		31.90%
Expected life (in years)	'3 years 2 months 1 day	[1]	'4 years	[1]	'3 years 5 months 19 days	[1]	'4 years 11 days	[1]
Employee Stock Purchase Plan	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Expected dividend yield	0.00%	[2]	0.00%	[2]	0.00%	[2]	0.00%	[2]
Risk-free interest rate	0.10%	[1],[2]	0.80%	[1],[2]	0.10%	[1],[2]	1.10%	[1],[2]
Expected volatility	32.00%	[2]	31.20%	[2]	30.30%	[2]	33.10%	[2]
Expected life (in years)	'3 months	[1],[2]	'1 year 10 months 10 days	[1],[2]	'3 months	[1],[2]	'1 year 5 months 16 days	[1],[2]
[1]	Beginning in November 2012, the Employee Stock Purchase Plan was modified to consist of three-month offering periods.
[2]	Assumptions for the Employee Stock Purchase Plan relate to the annual average of the enrollment periods. During the year ended December 31, 2012, enrollment was permitted in May and November of each year. Beginning in 2013, enrollment is permitted in February, May, August, and November of each year.

Restricted_Stock_Awards_and_Re

Restricted Stock Awards and Restricted Stock Units Activity (Detail) (Restricted Stock Awards And Units, USD $)	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013
Restricted Stock Awards And Units	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Awarded and unvested, Beginning balance	33,801	[1]
Granted	28,140	[1]
Assumed	2,364
Vested	-11,759
Forfeited	-5,805
Awarded and unvested, Ending balance	46,741	[1]
Weighted-average grant date fair value, Beginning balance	$17.63	[1]
Weighted-average grant date fair value, granted shares	$23.34	[1]
Weighted-average grant date fair value, Assumed	$26.24
Weighted-average grant date fair value, vested shares	$15.05
Weighted-average grant date fair value, forfeited shares	$17.33
Weighted-average grant date fair value, Ending balance	$22.19	[1]
[1]	Includes the maximum number of shares issuable under the Company's performance-based restricted stock unit awards.

Recovered_Sheet8

Restructuring Charges (Reversals), Net (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Employee severance pay and related costs	($2,827)	$11,467	($16,346)	$106,194
Non-cancelable lease, contract terminations, and other charges	2,251	11,436	11,739	16,309
Other non-cash charges	'	1,824	547	40,462
Sub-total before reversal of stock-based compensation expense	'	24,727	'	162,965
Reversal of stock-based compensation expense for forfeitures	'	'	'	-3,429
Restructuring charges (reversals), net	-576	24,727	-4,060	159,536
Restructuring Plans Prior to 2012	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Employee severance pay and related costs	-20	-44	-459	3,617
Non-cancelable lease, contract terminations, and other charges	2,217	2,104	11,652	6,360
Sub-total before reversal of stock-based compensation expense	'	2,060	'	9,977
Restructuring charges (reversals), net	2,197	2,060	11,193	9,977
Q2'12 Restructuring Plan	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Employee severance pay and related costs	-2,807	11,511	-15,784	102,577
Non-cancelable lease, contract terminations, and other charges	33	9,332	131	9,949
Other non-cash charges	'	1,824	'	40,462
Sub-total before reversal of stock-based compensation expense	'	22,667	'	152,988
Reversal of stock-based compensation expense for forfeitures	'	'	'	-3,429
Restructuring charges (reversals), net	-2,774	22,667	-15,653	149,559
Q4'12 Korea Business Closure	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Employee severance pay and related costs	'	'	-103	'
Non-cancelable lease, contract terminations, and other charges	1	'	-44	'
Other non-cash charges	'	'	547	'
Restructuring charges (reversals), net	$1	'	$400	'

Recovered_Sheet9

Restructuring Charges Reversals Net - Additional Information (Detail) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
			Person
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Other non-cash charges	'	$1,824,000	'	$547,000	$40,462,000	'
Changes in estimates and reversals of previous charges	'	'	'	-24,834,000	'	'
Restructuring charges, net	-576,000	24,727,000	'	-4,060,000	159,536,000	'
Restructuring liability	30,154,000	'	'	30,154,000	'	72,867,000
Employee Severance	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring charges, net	'	'	'	6,742,000	'	'
Restructuring liability	2,000,000	'	'	2,000,000	'	'
Non-Cancelable Lease Costs	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring liability	28,000,000	'	'	28,000,000	'	'
Americas	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring liability	20,190,000	'	'	20,190,000	'	42,689,000
EMEA	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring liability	8,851,000	'	'	8,851,000	'	18,144,000
Asia Pacific	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring liability	1,113,000	'	'	1,113,000	'	12,034,000
2011 and Prior Restructuring Plans	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Total pretax charges in severance, facility and other related costs	2,000,000	'	'	11,000,000	'	'
2011 and Prior Restructuring Plans | Americas	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Total pretax charges in severance, facility and other related costs	2,000,000	2,000,000	'	7,000,000	10,000,000	'
2011 and Prior Restructuring Plans | EMEA	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Total pretax charges in severance, facility and other related costs	'	'	'	4,000,000	'	'
Q2'12 Restructuring Plan	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Total pretax charges in severance, facility and other related costs	'	35,000,000	'	'	127,000,000	'
Number of employees whose employment was terminated	'	'	2,000	'	'	'
Other non-cash charges	'	1,824,000	'	'	40,462,000	'
Changes in estimates and reversals of previous charges	'	-14,000,000	'	-22,055,000	-17,000,000	'
Restructuring charges, net	-2,774,000	22,667,000	'	-15,653,000	149,559,000	'
Restructuring charges, net	-3,000	'	'	-16,000	'	'
Restructuring liability	3,788,000	'	'	3,788,000	'	35,049,000
Q2'12 Restructuring Plan | Employee Severance	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Changes in estimates and reversals of previous charges	3,000,000	'	'	'	'	'
Restructuring charges, net	'	'	'	6,271,000	'	'
Q2'12 Restructuring Plan | Americas	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring charges, net	'	11,000,000	'	'	97,000,000	'
Restructuring charges, net	'	'	'	-8,000,000	'	'
Q2'12 Restructuring Plan | EMEA	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring charges, net	'	12,000,000	'	'	47,000,000	'
Restructuring charges, net	-2,000,000	'	'	-7,000,000	'	'
Q2'12 Restructuring Plan | Asia Pacific	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring charges, net	'	'	'	'	6,000,000	'
Restructuring charges, net	-1,000,000	'	'	-1,000,000	'	'
Q4'12 Korea Business Closure	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Other non-cash charges	'	'	'	547,000	'	'
Changes in estimates and reversals of previous charges	'	'	'	-1,817,000	'	'
Restructuring charges, net	1,000	'	'	400,000	'	'
Restructuring liability	739,000	'	'	739,000	'	10,102,000
Q4'12 Korea Business Closure | Employee Severance	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Restructuring charges, net	'	'	'	443,000	'	'
Q4'12 Korea Business Closure | Asia Pacific	'	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'	'
Total pretax charges in severance, facility and other related costs	$1,000,000	'	'	$1,000,000	'	'

Restructuring_Accrual_Activity

Restructuring Accrual Activity (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Beginning balance	'	'	$72,867	'
Other non-cash charges, net	'	1,824	547	40,462
Changes in estimates and reversals of previous charges	'	'	-24,834	'
Restructuring charges, net	-576	24,727	-4,060	159,536
Cash paid	'	'	-37,827	'
Other non-cash charges	'	'	-547	'
Foreign currency	'	'	-279	'
Ending balance	30,154	'	30,154	'
Employee Severance	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Restructuring charges, net	'	'	6,742	'
Ending balance	2,000	'	2,000	'
Non-Cancelable Lease, Contract Termination, And Other Charges	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Restructuring charges, net	'	'	13,485	'
Restructuring Plans Prior to 2012	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Beginning balance	'	'	27,716	'
Changes in estimates and reversals of previous charges	'	'	-962	'
Restructuring charges, net	2,197	2,060	11,193	9,977
Cash paid	'	'	-13,424	'
Foreign currency	'	'	142	'
Ending balance	25,627	'	25,627	'
Restructuring Plans Prior to 2012 | Employee Severance	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Restructuring charges, net	'	'	28	'
Restructuring Plans Prior to 2012 | Non-Cancelable Lease, Contract Termination, And Other Charges	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Restructuring charges, net	'	'	12,127	'
Q2'12 Restructuring Plan	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Beginning balance	'	'	35,049	'
Other non-cash charges, net	'	1,824	'	40,462
Changes in estimates and reversals of previous charges	'	-14,000	-22,055	-17,000
Restructuring charges, net	-2,774	22,667	-15,653	149,559
Cash paid	'	'	-15,358	'
Foreign currency	'	'	-250	'
Ending balance	3,788	'	3,788	'
Q2'12 Restructuring Plan | Employee Severance	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Changes in estimates and reversals of previous charges	3,000	'	'	'
Restructuring charges, net	'	'	6,271	'
Q2'12 Restructuring Plan | Non-Cancelable Lease, Contract Termination, And Other Charges	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Restructuring charges, net	'	'	131	'
Q4'12 Korea Business Closure	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Beginning balance	'	'	10,102	'
Other non-cash charges, net	'	'	547	'
Changes in estimates and reversals of previous charges	'	'	-1,817	'
Restructuring charges, net	1	'	400	'
Cash paid	'	'	-9,045	'
Other non-cash charges	'	'	-547	'
Foreign currency	'	'	-171	'
Ending balance	739	'	739	'
Q4'12 Korea Business Closure | Employee Severance	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Restructuring charges, net	'	'	443	'
Q4'12 Korea Business Closure | Non-Cancelable Lease, Contract Termination, And Other Charges	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Restructuring charges, net	'	'	$1,227	'

Restructuring_Accruals_by_Segm

Restructuring Accruals by Segment (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Restructuring Cost and Reserve [Line Items]	'	'
Total restructuring accruals	$30,154	$72,867
Americas	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Total restructuring accruals	20,190	42,689
EMEA	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Total restructuring accruals	8,851	18,144
Asia Pacific	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Total restructuring accruals	$1,113	$12,034

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			1 Months Ended	12 Months Ended
Share data in Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 18, 2012	Dec. 31, 2012
						Alibaba Group	Alibaba Group
Income Taxes [Line Items]	'	'	'	'	'	'	'
Effective tax rate	32.00%	37.00%	24.00%	37.00%	'	'	'
Net tax benefit from foreign tax credits	'	'	$31,000,000	'	'	'	'
Net tax benefit from retroactively extended federal research and development credit	'	'	11,000,000	'	'	'	'
Undistributed earnings of foreign subsidiaries	2,500,000,000	'	2,500,000,000	'	2,000,000,000	'	'
Unrecognized tax benefits	703,000,000	'	703,000,000	'	'	'	'
Unrecognized tax benefits recorded on condensed consolidated balance sheets	621,000,000	'	621,000,000	'	'	'	'
Increase (decrease) in gross unrecognized tax benefit	'	'	-24,000,000	'	'	'	'
Unrecognized tax benefits, reasonably possible reduction in next twelve months	24,000,000	'	24,000,000	'	'	'	'
Sale of investments in equity interests, shares	'	'	'	'	'	523	523
Indirect tax assessed, not accrued	'	'	'	'	$85,000,000	'	'

Segment_Information_Detail

Segment Information (Detail) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	$1,138,973		$1,201,732		$3,414,585		$3,640,759
TAC	58,464		112,829		188,848		393,945
Revenue ex-TAC	1,080,509		1,088,903		3,225,737		3,246,814
Global operating costs	490,594	[1],[2]	396,269	[1],[2]	1,354,118	[1],[2]	1,228,686	[1],[2]
Depreciation and amortization	158,216		169,511		480,797		480,498
Stock-based compensation expense	80,726		61,366		193,467		166,903
Restructuring charges (reversals), net	-576		24,727		-4,060		159,536
Income from operations	92,759		152,189		415,708		376,378
Americas	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	850,935		843,731		2,521,667		2,501,515
TAC	36,435		41,289		111,077		130,154
Revenue ex-TAC	814,500		802,442		2,410,590		2,371,361
Direct costs by segment	171,285	[3]	189,345	[3]	513,677	[3]	550,080	[3]
EMEA	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	89,156		96,473		281,367		358,534
TAC	9,929		17,399		32,837		97,248
Revenue ex-TAC	79,227		79,074		248,530		261,286
Direct costs by segment	39,922	[3]	39,167	[3]	119,766	[3]	120,665	[3]
Asia Pacific	'		'		'		'
Segment Reporting Information [Line Items]	'		'		'		'
Revenue	198,882		261,528		611,551		780,710
TAC	12,100		54,141		44,934		166,543
Revenue ex-TAC	186,782		207,387		566,617		614,167
Direct costs by segment	$47,583	[3]	$56,329	[3]	$152,264	[3]	$164,068	[3]
[1]	The net cost reimbursements from Microsoft pursuant to the Search Agreement are primarily included in global operating costs.
[2]	Global operating costs include product development, service engineering and operations, general and administrative, and other corporate expenses that are managed on a global basis and that are not directly attributable to any segment.
[3]	Direct costs for each segment include cost of revenue-other as well as other operating expenses that are directly attributable to the segment such as employee compensation expense (excluding stock-based compensation expense), local sales and marketing expenses, and facilities expenses.

Capital_Expenditures_by_Segmen

Capital Expenditures by Segment (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Total capital expenditures, net	$77,653	$139,865	$229,310	$355,787
Americas	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total capital expenditures, net	70,044	122,812	210,521	302,139
EMEA	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total capital expenditures, net	2,817	9,238	8,481	22,599
Asia Pacific	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total capital expenditures, net	$4,792	$7,815	$10,308	$31,049

Property_and_Equipment_Net_by_

Property and Equipment Net by Segment (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Segment Reporting Information [Line Items]	'	'
Total property and equipment, net	$1,536,362	$1,685,845
United States	'	'
Segment Reporting Information [Line Items]	'	'
Total property and equipment, net	1,383,769	1,483,225
Other Americas	'	'
Segment Reporting Information [Line Items]	'	'
Total property and equipment, net	1,428	1,869
Americas	'	'
Segment Reporting Information [Line Items]	'	'
Total property and equipment, net	1,385,197	1,485,094
EMEA	'	'
Segment Reporting Information [Line Items]	'	'
Total property and equipment, net	48,183	59,416
Asia Pacific	'	'
Segment Reporting Information [Line Items]	'	'
Total property and equipment, net	$102,982	$141,335

Revenues_for_Groups_of_Similar

Revenues for Groups of Similar Services (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue from External Customer [Line Items]	'	'	'	'
Display	$469,932	$506,002	$1,396,745	$1,552,191
Search	435,192	472,537	1,278,081	1,403,903
Other	233,849	223,193	739,759	684,665
Total revenue	1,138,973	1,201,732	3,414,585	3,640,759
United States	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Total revenue	812,048	800,984	2,401,527	2,379,955
International	'	'	'	'
Revenue from External Customer [Line Items]	'	'	'	'
Total revenue	$326,925	$400,748	$1,013,058	$1,260,804

Recovered_Sheet10

Search Agreement with Microsoft Corporation - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
			M
Search Agreement With Microsoft Corporation [Line Items]	'	'	'	'	'
Term of license of core search technology with Microsoft, years	'	'	'10 years	'	'
Term of search agreement with Microsoft, years	'	'	'10 years	'	'
Revenue attributable to Search Agreement	31.00%	27.00%	30.00%	24.00%	'
Revenue share rate from Microsoft's services under the Search Agreement, to be received in first five years	'	'	88.00%	'	'
Revenue share rate from Microsoft's services under the Search Agreement, Affiliate revenue	'	'	88.00%	'	'
Revenue share rate from Microsoft's services under the Search Agreement, if Microsoft exercises sales exclusivity	'	'	93.00%	'	'
Revenue share rate from Microsoft's services under the Search Agreement, if the Company exercises its option to retain sales exclusivity	'	'	83.00%	'	'
Revenue share rate from Microsoft's services under the Search Agreement, no exercise of options regarding sales exclusivity	'	'	90.00%	'	'
Revenue collected from Search Agreement	'	'	$24	'	'
Uncollected Search Agreement revenue	'	'	251,000,000	'	258,000,000
Term after transition of paid services for which revenue guaranteed by Microsoft under Search Agreement (in months)	'	'	18	'	'
Classified as part of prepaid expenses and other current assets	'	'	8,000,000	'	5,000,000
Search Operating Costs	'	'	'	'	'
Search Agreement With Microsoft Corporation [Line Items]	'	'	'	'	'
Reimbursements for costs	11,000,000	17,000,000	$42,000,000	51,000,000	'

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (USD $)

9 Months Ended

1 Months Ended

1 Months Ended

In Millions, except Per Share data, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Nov. 08, 2013

Oct. 10, 2013

Oct. 10, 2013

Oct. 14, 2013

Oct. 31, 2013

Nov. 12, 2013

Alibaba Group

Foreign currency derivative

Foreign currency derivative

Net Investment Hedging

Net Investment Hedging

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Subsequent Event

Foreign currency derivative

Foreign currency derivative

Amendment No. 1

Alibaba Group

Net Investment Hedging

Total shares repurchased post Q3 to date of filing

Foreign currency derivative

Subsequent Event [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Repurchases of common stock, shares

'

'

'

'

'

'

'

'

'

'

'

1.2

Repurchases of common stock, value

'

'

'

'

'

'

'

'

'

'

'

$41

Average purchase price per share of common stock repurchased during the period

'

'

'

'

'

'

'

'

'

'

'

$33.37

Cash received for settlement of Hedge

'

'

'

'

'

'

'

'

'

'

158

'

Foreign currency derivative contract, notional amount

'

'

2,900

3,400

2,500

3,000

'

'

'

'

2,300

'

Maximum number of shares required to sell in connection with Qualified IPO

'

261.5

'

'

'

'

'

'

'

208

'

'

Unsecured revolving credit facility expiration date

18-Oct-13

'

'

'

'

'

'

18-Oct-13

9-Oct-14

'

'

'

Unsecured revolving credit facility

750

'

'

'

'

'

'

750

'

'

'

'

Unsecured revolving credit facility, additional commitment

250

'

'

'

'

'

'

250

'

'

'

'

Aggregate consideration for sale of patents

'

'

'

'

'

'

$70

'

'

'

'

'