Stockholders' Equity And Stock-Based Compensation (Narrative) (Details)		1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 07, 2017 USD ($) $ / shares shares	Jun. 30, 2017 item $ / shares shares	Jun. 30, 2017 USD ($) item $ / shares shares	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) item $ / shares shares	Jun. 30, 2016 USD ($)	Dec. 31, 2016 $ / shares	May 31, 2016 USD ($)
Stockholders' Equity [Line Items]
Common stock, par value | $ / shares		$ 0.001	$ 0.001		$ 0.001		$ 0.001
Proceeds from issuance of common stock | $					$ 4,965,000	$ 20,915,000
Warrants outstanding		705,121	705,121		705,121
Number of equity compensation plans | item		3	3		3
Stock-based compensation expense | $			$ 2,790,000	$ 196,000	$ 3,053,000	389,000
2017 Equity Incentive Plan [Member]
Stockholders' Equity [Line Items]
Term period					10 years
General And Administrative [Member]
Stockholders' Equity [Line Items]
Stock-based compensation expense | $			2,305,000	147,000	$ 2,509,000	295,000
Research And Development [Member]
Stockholders' Equity [Line Items]
Stock-based compensation expense | $			$ 485,000	$ 49,000	$ 544,000	$ 94,000
Stock Options [Member]
Stockholders' Equity [Line Items]
Expected term					9 years 10 months 24 days
Expected volatility					80.00%
Risk-free interest rate					2.40%
Dividend yield					0.00%
Stock Options [Member] | Non Employees [Member]
Stockholders' Equity [Line Items]
Shares granted		0	0		0
Officer [Member]
Stockholders' Equity [Line Items]
Cliff vest date		Jun. 30, 2018
Officer [Member] | Restricted Stock Units [Member]
Stockholders' Equity [Line Items]
Shares granted		160,974	160,974		160,974
Stock-based compensation expense | $			$ 333,000		$ 333,000
Common Stock Warrants [Member]
Stockholders' Equity [Line Items]
Share of common stock to purchase either cash or net exercised					169,489
Common Stock [Member]
Stockholders' Equity [Line Items]
Shares issued					136,552
Common Stock [Member] | 2017 Equity Incentive Plan [Member]
Stockholders' Equity [Line Items]
Shares authorized		1,500,000	1,500,000		1,500,000
Common Stock [Member] | 2017 Employee Stock Purchase Plan [Member]
Stockholders' Equity [Line Items]
Shares authorized		250,000	250,000		250,000
Shares granted		0	0		0
Common Stock [Member] | Private Placement [Member]
Stockholders' Equity [Line Items]
Shares sold	819,673
Common stock, par value | $ / shares	$ 0.001
Price per share | $ / shares	$ 6.10
Net proceeds | $	$ 4,965,000
MDB Capital Group, LLC [Member] | Initial Public Offering [Member]
Stockholders' Equity [Line Items]
Value of warrants | $								$ 1,443,000