Stockholders' Equity and Employee Stock Option Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	$ 1,806	$ 1,171	$ 5,565	$ 6,744
Cost of product [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	166	221	462	627
Cost of service [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	31	29	82	62
Product development [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	619	1,017	1,874	2,811
Sales and marketing [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	455	307	1,460	1,510
General and administrative [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	$ 535	$ (403)	$ 1,687	$ 1,734