Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax provision at statutory tax rate									$ 792	$ 2,645	$ 3
State income taxes, net of federal impact									38	74	3
Research and development tax credit									(1,233)	(874)	(425)
Valuation allowance, net of federal impact									(193)	(167)	475
Impact of changes in enacted tax law											(8,276)
Adjustments to deferred taxes									41	277	506
Other, net									53	(20)	113
(Benefit) provision for income taxes	$ (557)	$ (577)	$ 384	$ 248	$ (441)	$ 460	$ 1,139	$ 777	$ (502)	$ 1,935	$ (7,601)