Computation of Basic and Diluted Net Income per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net income attributable to Yahoo! Inc.	$ 348,190	[1]	$ 296,656	[2]	$ 331,150	[3]	$ 390,285	[4]	$ 272,267	[5]	$ 3,160,238	[6]	$ 226,631	[7]	$ 286,343	[8]	$ 1,366,281	$ 3,945,479	$ 1,048,827
Less: Net income allocated to participating securities																	(28)	(56)	(15)
Net income attributable to Yahoo! Inc. common stockholders-basic																	1,366,253	3,945,423	1,048,812
Weighted average common shares	1,012,972	[1]	1,024,289	[2]	1,079,389	[3]	1,094,170	[4]	1,155,950	[5]	1,186,046	[6]	1,213,320	[7]	1,215,783	[8]	1,052,705	1,192,775	1,274,240
Net income attributable to Yahoo! Inc. common stockholders per share-basic	$ 0.34	[1]	$ 0.29	[2]	$ 0.31	[3]	$ 0.36	[4]	$ 0.24	[5]	$ 2.66	[6]	$ 0.19	[7]	$ 0.24	[8]	$ 1.30	$ 3.31	$ 0.82
Net income attributable to Yahoo! Inc.	348,190	[1]	296,656	[2]	331,150	[3]	390,285	[4]	272,267	[5]	3,160,238	[6]	226,631	[7]	286,343	[8]	1,366,281	3,945,479	1,048,827
Less: Net income allocated to participating securities																	(28)	(55)	(14)
Less: Effect of dilutive securities issued by equity investees																	(16,656)	(4,920)	(2,698)
Net income attributable to Yahoo! Inc. common stockholders-diluted																	$ 1,349,597	$ 3,940,504	$ 1,046,115
Denominator for basic calculation	1,012,972	[1]	1,024,289	[2]	1,079,389	[3]	1,094,170	[4]	1,155,950	[5]	1,186,046	[6]	1,213,320	[7]	1,215,783	[8]	1,052,705	1,192,775	1,274,240
Restricted stock and restricted stock units																	14,097	8,403	5,347
Stock options and employee stock purchase plan																	4,009	1,728	2,695
Denominator for diluted calculation	1,038,754	[1]	1,041,698	[2]	1,094,694	[3]	1,108,095	[4]	1,168,336	[5]	1,195,085	[6]	1,221,719	[7]	1,226,486	[8]	1,070,811	1,202,906	1,282,282
Net income attributable to Yahoo! Inc. common stockholders per share-diluted	$ 0.33	[1]	$ 0.28	[2]	$ 0.30	[3]	$ 0.35	[4]	$ 0.23	[5]	$ 2.64	[6]	$ 0.18	[7]	$ 0.23	[8]	$ 1.26	$ 3.28	$ 0.82

[1] Net income attributable to Yahoo! Inc. for the quarter ended December 31, 2013 includes a gain on the sale of patents of $70 million, a goodwill impairment charge of $64 million, and net restructuring charges of $8 million.

[2] Net income attributable to Yahoo! Inc. for the quarter ended September 30, 2013 includes net restructuring reversals of less than $1 million.

[3] Net income attributable to Yahoo! Inc. for the quarter ended June 30, 2013 includes net restructuring charges of $4 million.

[4] Net income attributable to Yahoo! Inc. for the quarter ended March 31, 2013 includes net restructuring reversals of $7 million.

[5] Net income attributable to Yahoo! Inc. for the quarter ended December 31, 2012 includes a one-time distribution of foreign earnings resulting in an overall net benefit of approximately $117 million and net restructuring charges of $77 million.

[6] Net income attributable to Yahoo! Inc. for the quarter ended September 30, 2012 includes net restructuring charges of $25 million and pre-tax gain of $4.6 billion related to the sale of Alibaba Group Shares, which is included in other income, net.

[7] Net income attributable to Yahoo! Inc. for the quarter ended June 30, 2012 includes net restructuring charges of $129 million.

[8] Net income attributable to Yahoo! Inc. for the quarter ended March 31, 2012 includes net restructuring charges of $6 million.