Stockholders' Equity And Stock-Based Compensation (Summary Of Stock Warrant Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Beginning Balance, Number of shares	2,598,659
Options granted, Number of shares	657,375
Options exercised, Number of shares	(144,508)
Options canceled, Number of shares	(147,839)
Options expired, Number of shares	(7,000)
Ending Balance, Number of shares	2,956,687	2,598,659
Beginning Balance, Weighted average exercise price per share	$ 16.88
Options granted, Weighted average exercise price per share	15.18
Options exercised, Weighted average exercise price per share	3.44
Options expired, Weighted average exercise price per share	19.99
Ending Balance, Weighted average exercise price per share	$ 17.04	$ 16.88
Weighted average remaining life	7 years 7 months 6 days	8 years 2 months 12 days
Warrants to purchase common stock [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Beginning Balance, Number of shares	249,709
Options granted, Number of shares
Options exercised, Number of shares	(36,224)
Options expired, Number of shares
Ending Balance, Number of shares	213,485	249,709
Beginning Balance, Weighted average exercise price per share	$ 4.14
Options granted, Weighted average exercise price per share
Options exercised, Weighted average exercise price per share	5.00
Options expired, Weighted average exercise price per share
Ending Balance, Weighted average exercise price per share	$ 4.00	$ 4.14
Weighted average remaining life	2 years 4 months 13 days	3 years 6 months 22 days