Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Allowance for estimated product returns	$ 800	$ 2,000
Accumulated other comprehensive loss reclassified to retained earnings as a result of the separation of the GoTo Business	$ 13,400
Minimum [Member] | License Update [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenue recognition, period for recognition	12 months
Maximum [Member] | License Update [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenue recognition, period for recognition	24 months
Accumulated Foreign Currency Adjustment [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Accumulated other comprehensive loss reclassified to retained earnings as a result of the separation of the GoTo Business	$ 13,400