Stockholders' Equity And Stock-Based Compensation (Narrative) (Details) - USD ($)					1 Months Ended	2 Months Ended	12 Months Ended
	Jan. 01, 2019	Dec. 06, 2018	Sep. 24, 2017	Feb. 07, 2017	Nov. 30, 2017	Jun. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014	Oct. 25, 2018
Stockholders' Equity [Line Items]
Common stock, par value							$ 0.001	$ 0.001
Common stock, shares issued							20,593,000	16,819,000
Options granted							657,375
Warrants exercised							144,508
Exercise price							$ 15.70
Total intrinsic value of options exercised							$ 1,800,000	$ 3,800,000	$ 0
Fair value of options vested							6,400,000	26,800,000	1,200,000
Total stock-based compensation expense							12,338,000	$ 10,926,000	870,000
Unrecognized compensation cost							$ 17,100,000
Weighted average remaining contractual life							2 years 3 months 18 days
2017 Employee Stock Purchase Plan [Member]
Stockholders' Equity [Line Items]
Common stock, shares issued							23,869
Shares authorized								250,000
Increase in shares available for issuance threshold of common stock outstanding, number of shares								450,000
Increase in shares available for issuance threshold of common stock outstanding, percent outstanding								1.50%
Shares available for grant							478,474
2017 Inducement Equity Incentive Plan [Member]
Stockholders' Equity [Line Items]
Term period								10 years
Shares authorized					1,000,000
2017 Plan [Member]
Stockholders' Equity [Line Items]
Term period								10 years
Shares authorized								1,500,000
Increase in shares available for issuance threshold of common stock outstanding, number of shares								1,200,000
Increase in shares available for issuance threshold of common stock outstanding, percent outstanding								4.00%
Shares available for grant							539,436
First Vesting Portion [Member] | 2017 Inducement Equity Incentive Plan [Member]
Stockholders' Equity [Line Items]
Vesting percentage								25.00%
Second Vesting Portion (Per Month) [Member] | 2017 Inducement Equity Incentive Plan [Member]
Stockholders' Equity [Line Items]
Vesting period								36 months
Vesting percentage								8.33%
Sales, general and administrative [Member]
Stockholders' Equity [Line Items]
Total stock-based compensation expense							$ 9,004,000	$ 9,136,000	674,000
Research and development [Member]
Stockholders' Equity [Line Items]
Total stock-based compensation expense							3,334,000	$ 1,790,000	$ 196,000
Restricted Stock Units [Member]
Stockholders' Equity [Line Items]
Units granted during period								0
Reduction to APIC from shares withheld for tax								$ 100,000
Total stock-based compensation expense							$ 2,100,000	$ 2,900,000
Warrants to purchase common stock [Member]
Stockholders' Equity [Line Items]
Options granted
Warrants exercised							36,224
Aggregate intrinsic value exercisable options							$ 1,600,000
Performance Shares [Member]
Stockholders' Equity [Line Items]
Options granted							42,500
Subsequent Event [Member] | 2017 Plan [Member]
Stockholders' Equity [Line Items]
Additional common stock reserved for issuance	823,716
Initial Public Offering [Member]
Stockholders' Equity [Line Items]
Proceeds from issuance of common stock						$ 20,300,000
Common stock, shares issued						5,749,846
Directors [Member]
Stockholders' Equity [Line Items]
Total stock-based compensation expense					$ 1,200,000
Officer [Member] | Restricted Stock Units [Member]
Stockholders' Equity [Line Items]
Cliff vest date							Jun. 30, 2018
Shares available for grant								160,974
Unrecognized compensation cost							$ 0
Certain Employees [Member] | Restricted Stock Units [Member]
Stockholders' Equity [Line Items]
Shares available for grant								68,800
Total stock-based compensation expense							400,000	$ 100,000
Unrecognized compensation cost							$ 900,000
Certain Employees [Member] | Restricted Stock Units [Member] | First Vesting Portion [Member]
Stockholders' Equity [Line Items]
Vesting percentage								50.00%
Cliff vest date							Jun. 01, 2019
Certain Employees [Member] | Restricted Stock Units [Member] | Second Vesting Portion (Per Month) [Member]
Stockholders' Equity [Line Items]
Vesting percentage								50.00%
Cliff vest date							Jun. 01, 2021
Certain Employees [Member] | Restricted Stock Units [Member] | Change In Control [Member]
Stockholders' Equity [Line Items]
Vesting percentage								100.00%
Common Stock
Stockholders' Equity [Line Items]
Warrants exercised							145,000	162,000
Number of common shares called by issuance of warrants							23,957
Common Stock | 2017 Inducement Equity Incentive Plan [Member]
Stockholders' Equity [Line Items]
Shares authorized							541,625
Common Stock | Rights Offering [Member]
Stockholders' Equity [Line Items]
Net proceeds		$ 44,800,000
Right entitlement to holder		3,581,148									0.19860755
Exercise price of warrants/rights		$ 12.57									$ 12.57
Common Stock | Warrants to purchase common stock [Member]
Stockholders' Equity [Line Items]
Warrants exercised							24,000	522,000
Common Stock | Initial Public Offering [Member]
Stockholders' Equity [Line Items]
Price per share						$ 4.00
Common Stock | Private Placement [Member]
Stockholders' Equity [Line Items]
Shares sold			2,000,000	819,673
Common stock, par value			$ 0.001	$ 0.001
Price per share			$ 15.02	$ 6.10
Net proceeds			$ 29,900,000	$ 5,000,000
Shares issued								2,820,000
Common Stock | Chairman, Robert W. Duggan [Member] | Rights Offering [Member]
Stockholders' Equity [Line Items]
Ownership percentage		35.00%					44.00%
Shares purchased		3,146,226
Investment		$ 39,500,000
MDB Capital Group, LLC [Member] | Initial Public Offering [Member]
Stockholders' Equity [Line Items]
Price per share									$ 5.00
Value of warrants/rights							$ 1,400,000
Warrants/rights outstanding							121,609
Exercisable period of warrants or rights							5 years
Number of common shares called by issuance of warrants									574,985
MDB Capital Group, LLC [Member] | Private Placement [Member]
Stockholders' Equity [Line Items]
Price per share										$ 2.67
Warrants/rights outstanding							91,876
Exercisable period of warrants or rights										7 years
Number of common shares called by issuance of warrants										299,625