Condensed Consolidated Statements Of Operations and Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Income Statement [Abstract]
Revenues	$ 214,142	$ 189,844	$ 419,868	$ 371,367
Costs and expenses:
Cost of revenues	42,844	40,667	84,100	81,536
Sales and marketing	26,313	22,179	54,128	44,570
Research and development	15,461	13,074	30,226	26,668
General and administrative	22,726	28,206	46,234	61,835
Restructuring charges	(182)	3,659	(730)	9,189
Total costs and expenses	107,162	107,785	213,958	223,798
Operating income	106,980	82,059	205,910	147,569
Interest expense	(12,580)	(111,856)	(24,920)	(123,676)
Non-operating income, net	(2,097)	6,149	(1,290)	11,627
Income from continuing operations before income taxes	92,303	(23,648)	179,700	35,520
Income tax expense	(23,831)	15,967	(45,123)	(908)
Income from continuing operations, net of tax	68,472	(7,681)	134,577	34,612
Income (loss) from discontinued operations, net of tax	0	(2,929)	1,904	(4,451)
Net income	68,472	(10,610)	136,481	30,161
Foreign currency translation adjustments	0	48	0	76
Change in unrealized gain on investments, net of tax	42	1,077	37	609
Realized gain on investments, net of tax, included in net income	(30)	(1,398)	(35)	(1,415)
Other comprehensive loss	12	(273)	2	(730)
Comprehensive income	$ 68,484	$ (10,883)	$ 136,483	$ 29,431
Basic income (loss) per share
Continuing operations	$ 0.43	$ (0.05)	$ 0.85	$ 0.20
Discontinued operations	$ 0.00	$ (0.01)	$ 0.01	$ (0.02)
Net income	$ 0.43	$ (0.06)	$ 0.86	$ 0.18
Diluted income (loss) per share
Continuing operations	$ 0.42	$ (0.05)	$ 0.82	$ 0.20
Discontinued operations	$ 0.00	$ (0.01)	$ 0.01	$ (0.02)
Net income	$ 0.42	$ (0.06)	$ 0.83	$ 0.18
Shares used to compute net income per share
Basic	157,599	167,471	158,471	169,751
Diluted	164,178	167,471	163,530	171,850