Stockholders' Equity and Employee Stock Option Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	$ 1,383	$ 2,817
Cost of product [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	143	249
Cost of service [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	15	36
Product development [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	542	1,045
Sales and marketing [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	308	661
General and administrative [Member]
Stock-based Compensation Expense
Stock-based Compensation Expense, Total	$ 375	$ 826