Research Grants And Agreements (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development expense	$ 5,080	$ 5,038	$ 3,960	$ 3,175	$ 2,864	$ 2,925	$ 2,130	$ 1,727	$ 17,253	$ 9,646	$ 5,506
Sponsored Research Agreement ("SRA") [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development expense									$ 700	800	900
ODURF [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Period of time for Sponsored Research Agreement ("SRA")									12 months
ODURF [Member] | Sponsored Research Agreement ("SRA") [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development budget									$ 600
Research and development expense									800	$ 700	$ 1,000
Remaining sponsorship	$ 100								$ 100