Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended				12 Months Ended
	Jan. 31, 2017	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Line Items]
Income tax expense (benefit)		$ (437)	$ 316	$ 27	$ 315		$ (121)	$ 342	$ (3)
U.S. federal corporate tax rate							35.00%	35.00%	35.00%
Tax Cuts and Jobs Act of 2017, Deferred Income Tax Benefit							$ 400
Reduction of operating loss carryforwards								$ 1,400
Scenario, Plan [Member]
Income Tax Disclosure [Line Items]
U.S. federal corporate tax rate						21.00%
Federal [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		419,200					419,200
State [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards		$ 362,000					362,000
License Agreement, Jinghua [Member]
Income Tax Disclosure [Line Items]
Change in deferred tax liability							400
Income tax expense (benefit)							100	300
Milestone payment	$ 2,000						$ 2,000	$ 2,000