Unrestricted Subsidiaries Unrestricted Subsidiaries (Financial Position) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Cash and cash equivalents	$ 272,368		$ 433,663	$ 514,997	$ 207,801
Accounts receivable	97,376		91,699
Prepaid expenses and other current assets	36,738		22,602
Deferred income taxes	7,787		2,013
Total current assets	499,679		646,183
Property and equipment, net	59,829		38,217
Tradenames, net	123,338		105,551
Patent and patent licenses, net	20,352		24,927
Customer Relationships, Net	205,760		163,766
Goodwill	772,916		635,675
Other purchased intangibles, net	16,637		17,556
Other assets	13,599		12,819
Total assets	1,764,999		1,705,202
Accounts payable and accrued expenses	89,638		95,310
Income taxes payable	62		0
Deferred revenue, current	75,117		63,457
Deferred Tax Liabilities, Net, Current	364		342
Total current liabilities	165,429		159,367
Deferred income taxes	66,206		61,960
Other long-term liabilities	27,039		22,416
Total liabilities	$ 893,033		$ 884,967
Commitments and contingencies
Common Stock, Value, Issued	$ 477		$ 474
Additional paid-in capital	289,196		273,304
Retained Earnings (Accumulated Deficit)	606,808		553,584
Accumulated Other Comprehensive Income (Loss), Net of Tax	(24,515)	$ (18,806)	(7,127)
Total liabilities and stockholders’ equity	1,764,999		1,705,202
Unrestricted Subsidiaries [Member]
Cash and cash equivalents	14,821		27,944
Accounts receivable	61,890		57,005
Prepaid expenses and other current assets	4,209		2,986
Deferred income taxes	5,216		5,292
Total current assets	86,136		93,227
Property and equipment, net	25,701		12,834
Tradenames, net	75,781		70,310
Patent and patent licenses, net	19,544		24,007
Customer Relationships, Net	65,311		55,925
Goodwill	276,010		245,613
Other purchased intangibles, net	6,634		8,901
Other assets	1,835		1,706
Total assets	556,952		512,523
Accounts payable and accrued expenses	49,354		40,296
Income taxes payable	0		316
Deferred revenue, current	6,101		5,277
Total current liabilities	55,455		45,889
Deferred income taxes	23,149		17,397
Other long-term liabilities	22,979		16,243
Total liabilities	231,583		189,529
Additional paid-in capital	319,280		317,932
Retained Earnings (Accumulated Deficit)	7,700		6,051
Accumulated Other Comprehensive Income (Loss), Net of Tax	(1,611)		(989)
Stockholders' Equity Attributable to Parent	325,369		322,994
Total liabilities and stockholders’ equity	556,952		512,523
Notes Payable, Related Parties, Noncurrent	$ 130,000		$ 110,000