Income Taxes (Net Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets [Abstract]
United States federal net operating loss carryforwards	$ 70,564	$ 67,451
Deferred expenses	297	314
Research and development tax credit carryforwards	13,025	13,350
Right of use tax assets	771	2,103
Stock-based compensation	1,547	1,498
State net operating loss carryforwards	9,611	8,516
Foreign net operating loss carryforwards	27,433	27,589
Deferred revenue	36	27
Equipment, software, and leasehold improvements	1,402	1,841
Intangibles	6,066	7,392
Other	2,770	1,370
Gross deferred tax assets	133,522	131,451
Less valuation allowance	(131,522)	(128,314)
Gross deferred tax assets, net of valuation allowance	2,000	3,137
Deferred tax liabilities:
Other intangible assets	(146)	(158)
Right of use tax liability	668	(1,579)
Undistributed foreign earnings	954	937
Other	(637)	(683)
Gross deferred tax liabilities	(2,405)	(3,357)
Net deferred tax liabilities	$ (405)	$ (220)