Condensed Consolidated Balance Sheets - Scenario, Unspecified [Domain] - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
ASSETS
Cash and cash equivalents	$ 415,930		$ 433,663	$ 591,881	$ 207,801
Short-term investments	97,188		96,206
Accounts receivable, net of allowances of $4,160 and $3,685, respectively	87,319		91,699
Prepaid expenses and other current assets	27,140		22,602
Deferred income taxes	4,514		2,013
Total current assets	632,091		646,183
Long-term investments	54,177		60,508
Property and equipment, net	36,778		38,217
Tradenames, net	103,843		105,551
Patent and patent licenses, net	21,857		24,927
Customer relationships, net	175,488		163,766
Goodwill	674,084		635,675
Other purchased intangibles, net	14,980		17,556
Other assets	13,511		12,819
Total assets	1,726,809		1,705,202
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	87,081		95,310
Income taxes payable	1,215		0
Deferred revenue, current	75,353		63,457
Capital Lease Obligations, Current	324		258
Deferred income taxes	362		342
Total current liabilities	164,335		159,367
Long-term Debt	597,209		593,350
Capital Lease Obligations, Noncurrent	195		141
Liability for uncertain tax positions	25,136		37,551
Deferred income taxes	63,267		61,960
Deferred revenue, non-current	8,222		10,182
Other long-term liabilities	19,242		22,416
Total liabilities	$ 877,606		$ 884,967
Commitments and contingencies
Common stock, $0.01 par value. Authorized 95,000,000; total issued and outstanding 47,641,831 and 47,409,514 shares, respectively	$ 476		$ 474
Additional paid-in capital	282,702		273,304
Retained Earnings (Accumulated Deficit)	584,831		553,584
Accumulated other comprehensive loss	(18,806)	$ (21,984)	(7,127)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	849,203		820,235
Total liabilities and stockholders' equity	1,726,809		1,705,202
Series A Preferred Stock [Member]
LIABILITIES AND STOCKHOLDERS' EQUITY
Preferred stock, $0.01 par value	0		0
Series B Preferred Stock [Member]
LIABILITIES AND STOCKHOLDERS' EQUITY
Preferred stock, $0.01 par value	$ 0		$ 0