Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Accounts payable and accrued expenses	$ 737	$ 954
Accrued payroll and related expenses	3,062	1,713
Stock-based compensation expense	3,531	2,668
Depreciation of property and equipment	2,579	3,061
Capitalized software	0	94
Non-compete agreements	0	0
Unbilled receivables and refund liabilities	2,216	2,029
Operating loss carry-forwards of foreign subsidiary	10,907	3,275
Federal operating loss carry-forwards	33,087	31,884
State operating loss carry-forwards	3,919	4,038
Other	1,181	883
Gross deferred tax assets	61,219	50,599
Less valuation allowance	50,114	45,565
Gross deferred tax assets net of valuation allowance	11,105	5,034
Intangible assets	2,299	2,775
Capitalized software	1,928	0
Other	4,609	898
Gross deferred tax liabilities	8,836	3,673
Net deferred tax assets	$ 2,269	$ 1,361