Income Taxes (Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Accounts payable and accrued expenses	$ 1,864	$ 2,088
Accrued payroll and related expenses	1,933	3,902
Stock-based compensation expense	9,811	9,221
Depreciation of property and equipment	5,836	3,746
Non-compete agreements	8	27
Operating loss carry-forwards of foreign subsidiary	1,690	1,501
Federal operating loss carry-forwards	31,003	27,494
Intangible assets	865	6,195
State operating loss carry-forwards	2,925	2,648
Other	2,165	3,243
Gross deferred tax assets	58,100	60,065
Less valuation allowance	48,453	48,489
Gross deferred tax assets net of valuation allowance	9,647	11,576
Intangible assets	3,970	5,790
Unbilled receivables and refund liabilities	1,765	2,538
Capitalized software	984	969
Other	1,220	675
Gross deferred tax liabilities	7,939	9,972
Net deferred tax assets	$ 1,708	$ 1,604