Consolidated Statements of Income (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Income Statement [Abstract]
Revenues	$ 160,762	$ 188,882	$ 487,054	$ 509,120
Costs of revenues	107,966	107,664	321,304	312,581
Gross profit	52,796	81,218	165,750	196,539
Product development	724	1,450	1,147	2,057
Selling, general and administrative expenses	26,851	26,478	86,533	77,739
Operating income	25,221	53,290	78,070	116,743
Interest income, net	142	160	403	390
Other income, net	1,334	2,343	5,393	6,440
Decrease (increase) in income tax benefit payable to former stockholder	555	(18,012)	5,319	(34,868)
Income before income taxes	27,252	37,781	89,185	88,705
Provision (benefit) for income taxes	7,598	(1,980)	26,663	3,300
Net income	$ 19,654	$ 39,761	$ 62,522	$ 85,405
Basic net income per share	$ 0.24	$ 0.47	$ 0.75	$ 1.00
Diluted net income per share	$ 0.23	$ 0.47	$ 0.74	$ 0.98
Shares used in computing net income per share
Basic	83,405	83,946	83,640	85,491
Diluted	84,791	85,496	84,764	87,503