GOODWILL AND INTANGIBLE ASSETS - SCHEDULE OF INTANGIBLE ASSETS WITH DEFINITE LIVES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Intangible assets with definite lives
Gross carrying amount	$ 194,237	$ 185,639
Accumulated amortization	(133,546)	(98,937)
Total	$ 60,691	$ 86,702
Weighted-average useful life (years)	3 years 3 months 18 days	3 years 4 months 24 days
Content
Intangible assets with definite lives
Gross carrying amount	$ 62,082	$ 62,602
Accumulated amortization	(48,937)	(36,988)
Total	$ 13,145	$ 25,614
Weighted-average useful life (years)	4 years 1 month 6 days	4 years 1 month 6 days
Technology
Intangible assets with definite lives
Gross carrying amount	$ 55,487	$ 54,981
Accumulated amortization	(37,012)	(20,988)
Total	$ 18,475	$ 33,993
Weighted-average useful life (years)	3 years 2 months 12 days	3 years 2 months 12 days
Trade Names
Intangible assets with definite lives
Gross carrying amount	$ 32,123	$ 30,110
Accumulated amortization	(26,268)	(21,681)
Total	$ 5,855	$ 8,429
Weighted-average useful life (years)	2 years 6 months	2 years 7 months 6 days
Customer Lists
Intangible assets with definite lives
Gross carrying amount	$ 28,836	$ 24,566
Accumulated amortization	(13,078)	(14,050)
Total	$ 15,758	$ 10,516
Weighted-average useful life (years)	2 years 1 month 6 days	2 years 7 months 6 days
Advertiser and Supplier Relationships
Intangible assets with definite lives
Gross carrying amount	$ 15,709	$ 13,380
Accumulated amortization	(8,251)	(5,230)
Total	$ 7,458	$ 8,150
Weighted-average useful life (years)	4 years 2 months 12 days	4 years