UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and Cash Equivalents, at Carrying Value	$ 29,860	$ 23,940
Allowance for Doubtful Accounts Receivable, Current	619	629
Accounts Receivable, after Allowance for Credit Loss, Current	12,858	10,229
Deferred Costs, Current	91	196
Marketable Securities	3,973	9,965
Prepaid Expense and Other Assets, Current	6,428	3,480
Total current assets	53,210	47,810
Equipment, software, and leasehold improvements, at cost:
Equipment And Software Gross	29,790	30,726
Leasehold Improvements, Gross	2,745	2,776
Total equipment, software, and leasehold improvements	32,535	33,502
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	30,998	31,631
Net equipment, software, and leasehold improvements	1,537	1,871
Operating Lease, Right-of-Use Asset	4,987	7,937
Restricted Cash and Investments, Noncurrent	1,630	1,630
Other Assets, Noncurrent	982	4,150
Deferred Costs, Noncurrent	0	74
Deferred Income Tax Assets, Net	875	909
Goodwill	17,229	17,375
Total assets	80,450	81,756
Current liabilities:
Accounts Payable, Current	2,932	2,750
Accrued Expenses And Other Current Liabilities	12,336	17,850
Deferred Revenue, Current	2,281	2,122
Total current liabilities	17,549	22,722
Deferred Revenue, Noncurrent	27	45
Deferred Income Tax Liabilities, Net	1,100	1,129
Operating Lease, Liability, Noncurrent	5,896	6,837
Long-term Debt	0	2,895
Other Liabilities, Noncurrent	53	2,241
Total liabilities	$ 24,625	$ 35,869
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock, par value (USD per share)	$ 0.001	$ 0.001
Additional Paid in Capital	$ 677,498	$ 655,606
Accumulated Other Comprehensive Income (Loss), Net of Tax	(61,071)	(60,641)
Retained Earnings (Accumulated Deficit)	(560,657)	(548,862)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	55,825	46,149
Stockholders' Equity Attributable to Noncontrolling Interest	0	(262)
Stockholders' Equity Attributable to Parent, Total	55,825	45,887
Total liabilities and equity	80,450	81,756
Preferred stock, Series A
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock	0	0
Series B Preferred Stock
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock	8	8
Preferred stock, Undesignated series
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock	0	0
Common Stock [Member]
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common Stock, Value, Issued	$ 47	$ 38