The Company and Summary of Significant Accounting Policies (Details 4) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Research and Development Costs
Research and development costs incurred	$ 14,160	$ 11,833	$ 8,111
Advertising, Marketing, and Promotion Costs
Advertising, marketing, and promotion expenses	57,259	33,104	28,727
Prepaid advertising, marketing, and promotion expenses	139	368
Income Taxes
Minimum percentage used for determination of recognition of effect of income tax position if position more likely than not of being sustained	50.00%
Reconciliations of basic to diluted weighted-average common shares outstanding
Weighted-average shares used in basic computation	38,605,000	38,615,000	39,024,000
Dilutive effect of stock based award (in shares)	660,000	677,000	369,000
Weighted-average shares used for diluted computation	39,265,000	39,292,000	39,393,000
Contingent Consideration Arrangement
Reconciliation of beginning and ending amounts related to the fair value for contingent consideration for acquisition of business, categorized as Level 3
Contingent consideration for acquisition of business	88,100
Change in fair value	3,500
Balance at the end of the period	$ 91,600