Guarantor And Non-Guarantor Supplemental Financial Information (Schedule Of Statement Of Operations Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Revenue	$ 787,133	$ 1,020,450	$ 913,591	$ 727,835	$ 737,591	$ 898,099	$ 751,537	$ 646,418	$ 3,449,009		$ 3,033,645		$ 2,743,051
Costs and expenses:
Cost of revenue									761,272	[1]	685,487	[1]	602,682	[1]
Selling and marketing (including $211,018, $171,110 and $139,714 with a related party)									1,474,641	[1]	1,234,781	[1]	1,061,097	[1]
Technology and content									380,999	[1]	308,780	[1]	282,634	[1]
General and administrative									309,708	[1]	258,604	[1]	272,853	[1]
Amortization of intangible assets									21,925		22,514		23,875
Legal reserves, occupancy tax and other									20,855		22,692		67,999
Restructuring charges													34,168
Operating income	91,645	209,099	143,707	35,158	112,935	209,154	126,536	52,162	479,609		500,787		397,743
Other income (expense):
Other, net									(77,537)		(74,948)		(77,967)
Total other expense, net									(77,537)		(74,948)		(77,967)
Income before income taxes									402,072		425,839		319,776
Provision for income taxes									(75,731)		(120,342)		(101,502)
Income from continuing operations									326,341		305,497		218,274
Discontinued operations, net of taxes									148,262		120,063		85,349
Net income									474,603		425,560		303,623
Net income attributable to noncontrolling interests									(2,309)		(4,060)		(4,097)
Net income	70,328	209,534	140,393	52,039	71,293	176,550	114,262	59,395	472,294		421,500		299,526
Parent [Member]
Other income (expense):
Equity in pre-tax earnings of consolidated subsidiaries									382,403		341,750		240,115
Other, net									(83,421)		(56,193)		(37,999)
Total other expense, net									298,982		285,557		202,116
Income before income taxes									298,982		285,557		202,116
Provision for income taxes									25,050		15,880		12,061
Income from continuing operations									324,032		301,437		214,177
Discontinued operations, net of taxes									148,262		120,063		85,349
Net income									472,294		421,500		299,526
Net income									472,294		421,500		299,526
Guarantor Subsidiaries [Member]
Revenue									3,041,755		2,679,420		2,375,142
Costs and expenses:
Cost of revenue									648,219		590,236		495,029
Selling and marketing (including $211,018, $171,110 and $139,714 with a related party)									1,088,145		917,344		730,272
Technology and content									297,859		255,306		231,775
General and administrative									213,594		181,920		195,741
Amortization of intangible assets									4,988		5,071		6,596
Legal reserves, occupancy tax and other									20,855		22,692		67,999
Restructuring charges													8,761
Intercompany (income) expense, net									597,105		347,361		232,828
Operating income									170,990		359,490		406,141
Other income (expense):
Equity in pre-tax earnings of consolidated subsidiaries									244,429		120,085		(21,017)
Other, net									44,288		(18,358)		(38,646)
Total other expense, net									288,717		101,727		(59,663)
Income before income taxes									459,707		461,217		346,478
Provision for income taxes									(73,165)		(115,126)		(103,205)
Income from continuing operations									386,542		346,091		243,273
Discontinued operations, net of taxes									140,200		142,150		107,671
Net income									526,742		488,241		350,944
Net income									526,742		488,241		350,944
Non-Guarantor Subsidiaries [Member]
Revenue									424,018		366,408		378,034
Costs and expenses:
Cost of revenue									111,868		96,372		111,910
Selling and marketing (including $211,018, $171,110 and $139,714 with a related party)									404,409		328,683		336,606
Technology and content									83,388		53,416		50,797
General and administrative									95,902		76,558		77,261
Amortization of intangible assets									16,937		17,443		17,279
Restructuring charges													25,407
Intercompany (income) expense, net									(597,105)		(347,361)		(232,828)
Operating income									308,619		141,297		(8,398)
Other income (expense):
Other, net									(38,404)		(397)		(1,322)
Total other expense, net									(38,404)		(397)		(1,322)
Income before income taxes									270,215		140,900		(9,720)
Provision for income taxes									(27,616)		(21,096)		(10,358)
Income from continuing operations									242,599		119,804		(20,078)
Discontinued operations, net of taxes									32,464		78,470		42,733
Net income									275,063		198,274		22,655
Net income attributable to noncontrolling interests									(2,309)		(4,060)		(4,097)
Net income									272,754		194,214		18,558
Eliminations [Member]
Revenue									(16,764)		(12,183)		(10,125)
Costs and expenses:
Cost of revenue									1,185		(1,121)		(4,257)
Selling and marketing (including $211,018, $171,110 and $139,714 with a related party)									(17,913)		(11,246)		(5,781)
Technology and content									(248)		58		62
General and administrative									212		126		(149)
Other income (expense):
Equity in pre-tax earnings of consolidated subsidiaries									(626,832)		(461,835)		(219,098)
Total other expense, net									(626,832)		(461,835)		(219,098)
Income before income taxes									(626,832)		(461,835)		(219,098)
Income from continuing operations									(626,832)		(461,835)		(219,098)
Discontinued operations, net of taxes									(172,664)		(220,620)		(150,404)
Net income									(799,496)		(682,455)		(369,502)
Net income									$ (799,496)		$ (682,455)		$ (369,502)

[1] Includes stock-based compensation as follows: Cost of revenue for year ended December 31, 2011, 2010, and 2009 were: $2,971, $2,401, and $2,285 in thousands respectively. Selling and marketing for year ended December 31, 2011, 2010, and 2009 were: $13,085, $11,766, and $10,555 in thousands respectively. Technology and content for year ended December 31, 2011, 2010, and 2009 were: $13,505, $11,665, and $13,424 in thousands respectively. General and administrative for year ended December 31, 2011, 2010, and 2009 were: $34,286, $26,675, and $29,492 in thousands respectively.