Condensed Consolidating Balance Sheets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011 As Restated [Member]		Dec. 31, 2010 As Restated [Member]		Sep. 30, 2012 Parent [Member]	Dec. 31, 2011 Parent [Member]	Sep. 30, 2011 Parent [Member] As Restated [Member]	Dec. 31, 2010 Parent [Member] As Restated [Member]	Sep. 30, 2012 Guarantor Subsidiaries [Member]	Dec. 31, 2011 Guarantor Subsidiaries [Member]	Sep. 30, 2011 Guarantor Subsidiaries [Member] As Restated [Member]	Dec. 31, 2010 Guarantor Subsidiaries [Member] As Restated [Member]	Sep. 30, 2012 Non-Guarantor Subsidiaries [Member]	Dec. 31, 2011 Non-Guarantor Subsidiaries [Member]	Sep. 30, 2011 Non-Guarantor Subsidiaries [Member] As Restated [Member]	Dec. 31, 2010 Non-Guarantor Subsidiaries [Member] As Restated [Member]	Sep. 30, 2012 Consolidation, Eliminations [Member]	Dec. 31, 2011 Consolidation, Eliminations [Member]	Sep. 30, 2011 Consolidation, Eliminations [Member] As Restated [Member]	Dec. 31, 2010 Consolidation, Eliminations [Member] As Restated [Member]
Current Assets:
Cash and cash equivalents	$ 408,284	$ 285,512	$ 289,658	[1]	$ 171,618	[1]	$ 150,354	$ 150,171	$ 150,114	$ 46,012	$ 184,934	$ 93,285	$ 99,556	$ 87,619	$ 72,996	$ 42,056	$ 39,988	$ 37,987	$ 0	$ 0	$ 0	$ 0
Restricted cash	3,004	8,733					0	0			2,794	8,515			210	218			0	0
Accounts receivable, net	96,814	114,778					0	0			75,458	89,656			21,356	25,122			0	0
Deferred tax assets—current portion	36,660	32,063					0	0			32,250	27,543			4,410	4,520			0	0
Prepaid expenses and other current assets	26,723	24,584					9,069	9,362			8,330	45			9,324	15,177			0	0
Total current assets	571,485	465,670					159,423	159,533			303,766	219,044			108,296	87,093			0	0
Non-Current Assets:
Restricted cash	410	652					0	0			0	0			410	652			0	0
Property and equipment, net	52,655	52,541					0	0			44,931	45,920			7,724	6,621			0	0
Goodwill	231,377	231,377					0	0			231,377	231,377			0	0			0	0
Other intangibles, net	108,185	141,882					0	0			108,185	141,882			0	0			0	0
Deferred tax assets—long-term portion	244,072	258,271					0	0			238,259	252,469			5,813	5,802			0	0
Other non-current assets	18,911	20,565					4,099	5,536			1,057	1,047			13,755	13,982			0	0
Investment in subsidiaries	0	0					277,123	235,908			10,070	41,030			0	0			(287,193)	(276,938)
Intercompany accounts	0	0					571,183	568,429			(560,795)	(580,202)			(10,388)	11,773			0	0
Total non-current assets	655,610	705,288					852,405	809,873			73,084	133,523			17,314	38,830			(287,193)	(276,938)
Total Assets	1,227,095	1,170,958					1,011,828	969,406			376,850	352,567			125,610	125,923			(287,193)	(276,938)
Current Liabilities:
Accounts payable	8,342	7,740					0	0			6,984	5,954			1,358	1,786			0	0
Accrued expenses and other liabilities	80,760	73,111					6,673	5,023			35,773	36,986			38,314	31,102			0	0
Deferred revenue—current portion	116,372	108,217					0	0			106,560	84,237			9,812	23,980			0	0
Total current liabilities	205,474	189,068					6,673	5,023			149,317	127,177			49,484	56,868			0	0
Non-Current Liabilities:
Long-term debt	273,626	273,210					273,626	273,210			0	0			0	0			0	0
Accrued exit and disposal obligations	2,773	3,926					0	0			466	1,142			2,307	2,784			0	0
Liability for uncertain tax positions	3,194	4,098					0	0			1,768	1,645			1,426	2,453			0	0
Deferred revenue—long-term portion	5,252	8,115					0	0			5,229	7,804			23	311			0	0
Other non-current liabilities	5,247	1,368					0	0			4,230	588			1,017	780			0	0
Total non-current liabilities	290,092	290,717					273,626	273,210			11,693	11,179			4,773	6,328			0	0
Total Liabilities	495,566	479,785					280,299	278,233			161,010	138,356			54,257	63,196			0	0
Total stockholders’ equity	731,529	691,173					731,529	691,173			215,840	214,211			71,353	62,727			(287,193)	(276,938)
Total liabilities and stockholders’ equity	$ 1,227,095	$ 1,170,958					$ 1,011,828	$ 969,406			$ 376,850	$ 352,567			$ 125,610	$ 125,923			$ (287,193)	$ (276,938)

[1] (1) As restated - See Note 14 “Restatement of Previously Issued Financial Statements” of Notes to Condensed Consolidated Financial Statements.See notes to Condensed Consolidated Financial Statements.