GOODWILL AND INTANGIBLE ASSETS (Details3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Intangible assets with definite lives
Gross Carrying Amount	$ 185,639	$ 152,317
Accumulated Amortization	(98,937)	(83,310)
Total	86,702	69,007
Weighted-Average Useful Life (Years)	3 years 4 months 24 days	3 years 2 months 12 days
Future amortization expense of intangible assets with definite-lives
2015	44,262
2016	24,099
2017	13,441
2018	4,547
2019	353
Total	86,702	69,007
Content
Intangible assets with definite lives
Gross Carrying Amount	62,602	47,800
Accumulated Amortization	(36,988)	(22,373)
Total	25,614	25,427
Weighted-Average Useful Life (Years)	4 years 1 month 6 days	4 years
Future amortization expense of intangible assets with definite-lives
Total	25,614	25,427
Technology
Intangible assets with definite lives
Gross Carrying Amount	54,981	41,694
Accumulated Amortization	(20,988)	(25,324)
Total	33,993	16,370
Weighted-Average Useful Life (Years)	3 years 2 months 12 days	2 years 10 months 24 days
Future amortization expense of intangible assets with definite-lives
Total	33,993	16,370
Trade names
Intangible assets with definite lives
Gross Carrying Amount	30,110	29,283
Accumulated Amortization	(21,681)	(16,427)
Total	8,429	12,856
Weighted-Average Useful Life (Years)	2 years 7 months 6 days	3 years
Future amortization expense of intangible assets with definite-lives
Total	8,429	12,856
Customer lists
Intangible assets with definite lives
Gross Carrying Amount	24,566	22,584
Accumulated Amortization	(14,050)	(13,116)
Total	10,516	9,468
Weighted-Average Useful Life (Years)	2 years 7 months 6 days	2 years 6 months
Future amortization expense of intangible assets with definite-lives
Total	10,516	9,468
Advertiser and supplier relationships
Intangible assets with definite lives
Gross Carrying Amount	13,380	10,956
Accumulated Amortization	(5,230)	(6,070)
Total	8,150	4,886
Weighted-Average Useful Life (Years)	4 years	2 years 10 months 24 days
Future amortization expense of intangible assets with definite-lives
Total	$ 8,150	$ 4,886