Income Taxes (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Components of deferred income taxes
Non-deductible reserves and accruals	$ 4,105	$ 3,125
Stock compensation	4,948	5,146
Net operating loss and other carryforwards	9,816	7,526
Gross deferred tax asset	18,869	15,797
Less - valuation allowance	(2,086)	(3,077)
Sub-total	16,783	12,720
Depreciation and amortization	(5,018)	(7,996)
Goodwill amortization	(4,381)	(5,518)
Other liabilities	(2,872)	(3,347)
Deferred commissions	(3,743)	(4,775)
Net deferred tax asset (liability)	$ 769	$ (8,916)