GUARANTOR CONDENSED CONSOLIDATING FINANCIAL STATEMENTS - CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Total revenues	$ 683,105	$ 619,544	$ 540,391
Total cost of revenues	163,719	139,553	115,442
Gross profit	519,386	479,991	424,949
Technology and development	97,105	94,221	85,723
Marketing and advertising	171,094	168,536	145,103
General and administrative	54,427	60,971	55,691
Amortization of acquired intangible assets	109,318	147,681	185,193
Total operating expenses	431,944	471,409	471,710
Income (loss) from operations	87,442	8,582	(46,761)
Interest expense, net	(81,056)	(69,680)	(97,837)
Other expense, net	(334)	(368)	(655)
Total income (loss) before income taxes	6,052	(61,466)	(145,253)
Income tax benefit (expense)	23,366	42,738	65,553
Income (loss) before loss from subsidiaries	29,418	(18,728)	(79,700)
Income (loss) from subsidiaries	0	0	0
Net income (loss)	29,418	(18,728)	(79,700)
Elimination [Member]
Total revenues	(12,355)	(17,575)	(19,525)
Total cost of revenues	(12,355)	(17,575)	(19,525)
Gross profit	0	0	0
Technology and development	0	0	0
Marketing and advertising	0	0	0
General and administrative	0	0	0
Amortization of acquired intangible assets	0	0	0
Total operating expenses	0	0	0
Income (loss) from operations	0	0	0
Interest expense, net	0	0	0
Other expense, net	0	0	0
Total income (loss) before income taxes	0	0	0
Income tax benefit (expense)	0	0	0
Income (loss) before loss from subsidiaries	0	0	0
Income (loss) from subsidiaries	(25,076)	129,572	286,175
Net income (loss)	(25,076)	129,572	286,175
Parent [Member]
Total revenues	0	0	0
Total cost of revenues	0	0	0
Gross profit	0	0	0
Technology and development	0	0	0
Marketing and advertising	0	0	0
General and administrative	0	0	0
Amortization of acquired intangible assets	0	0	0
Total operating expenses	0	0	0
Income (loss) from operations	0	0	0
Interest expense, net	0	0	0
Other expense, net	0	0	0
Total income (loss) before income taxes	0	0	0
Income tax benefit (expense)	0	0	0
Income (loss) before loss from subsidiaries	0	0	0
Income (loss) from subsidiaries	29,418	(18,728)	(79,700)
Net income (loss)	29,418	(18,728)	(79,700)
Issuer [Member]
Total revenues	0	0	0
Total cost of revenues	0	0	0
Gross profit	0	0	0
Technology and development	0	0	0
Marketing and advertising	0	0	0
General and administrative	522	5,628	500
Amortization of acquired intangible assets	0	0	0
Total operating expenses	522	5,628	500
Income (loss) from operations	(522)	(5,628)	(500)
Interest expense, net	(81,598)	(69,579)	(97,829)
Other expense, net	0	(8)	0
Total income (loss) before income taxes	(82,120)	(75,215)	(98,329)
Income tax benefit (expense)	30,081	25,446	35,890
Income (loss) before loss from subsidiaries	(52,039)	(49,769)	(62,439)
Income (loss) from subsidiaries	23,619	(30,874)	(71,902)
Net income (loss)	(28,420)	(80,643)	(134,341)
Guarantor Subsidiaries [Member]
Total revenues	681,709	617,633	537,910
Total cost of revenues	174,735	153,575	131,132
Gross profit	506,974	464,058	406,778
Technology and development	95,483	92,318	83,957
Marketing and advertising	163,060	158,359	131,585
General and administrative	51,687	52,542	52,531
Amortization of acquired intangible assets	109,318	147,681	185,193
Total operating expenses	419,548	450,900	453,266
Income (loss) from operations	87,426	13,158	(46,488)
Interest expense, net	542	(105)	(512)
Other expense, net	(305)	(150)	(474)
Total income (loss) before income taxes	87,663	12,903	(47,474)
Income tax benefit (expense)	(6,576)	17,465	29,798
Income (loss) before loss from subsidiaries	81,087	30,368	(17,676)
Income (loss) from subsidiaries	(27,961)	(79,970)	(134,242)
Net income (loss)	53,126	(49,602)	(151,918)
Non-Guarantor Subsidiaries [Member]
Total revenues	13,751	19,486	22,006
Total cost of revenues	1,339	3,553	3,835
Gross profit	12,412	15,933	18,171
Technology and development	1,622	1,903	1,766
Marketing and advertising	8,034	10,177	13,518
General and administrative	2,218	2,801	2,660
Amortization of acquired intangible assets	0	0	0
Total operating expenses	11,874	14,881	17,944
Income (loss) from operations	538	1,052	227
Interest expense, net	0	4	504
Other expense, net	(29)	(210)	(181)
Total income (loss) before income taxes	509	846	550
Income tax benefit (expense)	(139)	(173)	(135)
Income (loss) before loss from subsidiaries	370	673	415
Income (loss) from subsidiaries	0	0	(331)
Net income (loss)	$ 370	$ 673	$ 84