SEGMENT INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment reporting information
Revenue	$ 742,249	$ 640,600
Operating income	84,551	62,765
Operating Income Before Amortization	112,750	91,272
Depreciation	14,016	12,115
Reconciliation of Operating Income Before Amortization to operating income (loss) for the entity's reportable segments
Operating Income Before Amortization	112,750	91,272
Non-Cash Compensation Expense	(12,663)	(21,466)
Amortization of Intangibles	(14,078)	(7,041)
Acquisition-related Contingent Consideration Fair Value Adjustment	(1,458)
Operating income	84,551	62,765
Search and Applications
Segment reporting information
Revenue	397,192	343,198
Operating income	86,983	73,490
Operating Income Before Amortization	93,649	73,500
Depreciation	3,865	3,291
Reconciliation of Operating Income Before Amortization to operating income (loss) for the entity's reportable segments
Operating Income Before Amortization	93,649	73,500
Non-Cash Compensation Expense	(3)	(8)
Amortization of Intangibles	(6,663)	(2)
Operating income	86,983	73,490
Match
Segment reporting information
Revenue	188,862	174,275
Operating income	40,959	29,906
Operating Income Before Amortization	46,303	37,328
Depreciation	4,677	3,537
Reconciliation of Operating Income Before Amortization to operating income (loss) for the entity's reportable segments
Operating Income Before Amortization	46,303	37,328
Non-Cash Compensation Expense	157	(907)
Amortization of Intangibles	(4,043)	(6,515)
Acquisition-related Contingent Consideration Fair Value Adjustment	(1,458)
Operating income	40,959	29,906
Local
Segment reporting information
Revenue	74,945	77,119
Operating income	(3,403)	3,789
Operating Income Before Amortization	(1,001)	3,950
Depreciation	2,346	2,801
Reconciliation of Operating Income Before Amortization to operating income (loss) for the entity's reportable segments
Operating Income Before Amortization	(1,001)	3,950
Amortization of Intangibles	(2,402)	(161)
Operating income	(3,403)	3,789
Media
Segment reporting information
Revenue	45,315	15,911
Operating income	(8,828)	(6,669)
Operating Income Before Amortization	(8,374)	(6,401)
Depreciation	523	179
Reconciliation of Operating Income Before Amortization to operating income (loss) for the entity's reportable segments
Operating Income Before Amortization	(8,374)	(6,401)
Non-Cash Compensation Expense	(205)	(268)
Amortization of Intangibles	(249)
Operating income	(8,828)	(6,669)
Other
Segment reporting information
Revenue	36,045	30,206
Operating income	(3,222)	(1,714)
Operating Income Before Amortization	(2,499)	(1,398)
Depreciation	302	244
Reconciliation of Operating Income Before Amortization to operating income (loss) for the entity's reportable segments
Operating Income Before Amortization	(2,499)	(1,398)
Non-Cash Compensation Expense	(2)	47
Amortization of Intangibles	(721)	(363)
Operating income	(3,222)	(1,714)
Total Eliminations
Segment reporting information
Revenue	(110)	(109)
Corporate
Segment reporting information
Operating income	(27,938)	(36,037)
Operating Income Before Amortization	(15,328)	(15,707)
Depreciation	2,303	2,063
Reconciliation of Operating Income Before Amortization to operating income (loss) for the entity's reportable segments
Operating Income Before Amortization	(15,328)	(15,707)
Non-Cash Compensation Expense	(12,610)	(20,330)
Operating income	$ (27,938)	$ (36,037)