Condensed Consolidating Balance Sheets (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011 As Restated [Member]		Dec. 31, 2010 As Restated [Member]		Jun. 30, 2012 Parent [Member]	Dec. 31, 2011 Parent [Member]	Jun. 30, 2011 Parent [Member] As Restated [Member]	Dec. 31, 2010 Parent [Member] As Restated [Member]	Jun. 30, 2012 Guarantor Subsidiaries [Member]	Dec. 31, 2011 Guarantor Subsidiaries [Member]	Jun. 30, 2011 Guarantor Subsidiaries [Member] As Restated [Member]	Dec. 31, 2010 Guarantor Subsidiaries [Member] As Restated [Member]	Jun. 30, 2012 Non-Guarantor Subsidiaries [Member]	Dec. 31, 2011 Non-Guarantor Subsidiaries [Member]	Jun. 30, 2011 Non-Guarantor Subsidiaries [Member] As Restated [Member]	Dec. 31, 2010 Non-Guarantor Subsidiaries [Member] As Restated [Member]	Jun. 30, 2012 Consolidation, Eliminations [Member]	Dec. 31, 2011 Consolidation, Eliminations [Member]	Jun. 30, 2011 Consolidation, Eliminations [Member] As Restated [Member]	Dec. 31, 2010 Consolidation, Eliminations [Member] As Restated [Member]
Current Assets:
Cash and cash equivalents	$ 362,430	$ 285,512	$ 256,758	[1]	$ 171,618	[1]	$ 150,285	$ 150,171	$ 150,061	$ 46,012	$ 150,597	$ 93,285	$ 64,761	$ 87,619	$ 61,548	$ 42,056	$ 41,936	$ 37,987	$ 0	$ 0	$ 0	$ 0
Restricted cash	3,314	8,733					0	0			3,114	8,515			200	218			0	0
Accounts receivable, net	126,368	114,778					0	0			104,179	89,656			22,189	25,122			0	0
Deferred tax assets—current portion	36,540	32,063					0	0			32,204	27,543			4,336	4,520			0	0
Prepaid expenses and other current assets	24,240	24,584					5,439	9,362			9,900	45			8,901	15,177			0	0
Total current assets	552,892	465,670					155,724	159,533			299,994	219,044			97,174	87,093			0	0
Non-Current Assets:
Restricted cash	662	652					0	0			0	0			662	652			0	0
Property and equipment, net	52,831	52,541					0	0			46,135	45,920			6,696	6,621			0	0
Goodwill	231,377	231,377					0	0			231,377	231,377			0	0			0	0
Other intangibles, net	119,417	141,882					0	0			119,417	141,882			0	0			0	0
Deferred tax assets—long-term portion	248,796	258,271					0	0			243,304	252,469			5,492	5,802			0	0
Other non-current assets	19,668	20,565					4,578	5,536			1,066	1,047			14,024	13,982			0	0
Investment in subsidiaries	0	0					257,882	235,908			13,205	41,030			0	0			(271,087)	(276,938)
Intercompany accounts	0	0					570,210	568,429			(563,067)	(580,202)			(7,143)	11,773			0	0
Total non-current assets	672,751	705,288					832,670	809,873			91,437	133,523			19,731	38,830			(271,087)	(276,938)
Total Assets	1,225,643	1,170,958					988,394	969,406			391,431	352,567			116,905	125,923			(271,087)	(276,938)
Current Liabilities:
Accounts payable	10,375	7,740					0	0			8,663	5,954			1,712	1,786			0	0
Accrued expenses and other liabilities	71,381	73,111					2,609	5,023			38,547	36,986			30,225	31,102			0	0
Deferred revenue—current portion	140,284	108,217					0	0			126,888	84,237			13,396	23,980			0	0
Total current liabilities	222,040	189,068					2,609	5,023			174,098	127,177			45,333	56,868			0	0
Non-Current Liabilities:
Long-term debt	273,484	273,210					273,484	273,210			0	0			0	0			0	0
Accrued exit and disposal obligations	3,130	3,926					0	0			694	1,142			2,436	2,784			0	0
Liability for uncertain tax positions	4,119	4,098					0	0			1,689	1,645			2,430	2,453			0	0
Deferred revenue—long-term portion	5,399	8,115					0	0			5,376	7,804			23	311			0	0
Other non-current liabilities	5,170	1,368					0	0			4,215	588			955	780			0	0
Total non-current liabilities	291,302	290,717					273,484	273,210			11,974	11,179			5,844	6,328			0	0
Total Liabilities	513,342	479,785					276,093	278,233			186,072	138,356			51,177	63,196			0	0
Stockholders’ Equity	712,301	691,173					712,301	691,173			205,359	214,211			65,728	62,727			(271,087)	(276,938)
Total Liabilities and Stockholders’ Equity	$ 1,225,643	$ 1,170,958					$ 988,394	$ 969,406			$ 391,431	$ 352,567			$ 116,905	$ 125,923			$ (271,087)	$ (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.