Stockholders' Equity (Stock Option Activity) (Details)	6 Months Ended
	Jun. 30, 2019 $ / shares shares
Options
Balance at the beginning of the period (in shares) | shares	15,409,357
Options granted (in shares) | shares	728,610
Options exercised (in shares) | shares	(488,625)
Options Cancelled (forfeited) (in shares) | shares	(509,923)
Options Cancelled (expired) (in shares) | shares	(45)
Balance at the end of the period (in shares) | shares	15,139,374
Weighted Average Exercise Price (Per Share)
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 0.95
Options granted (in dollars per share) | $ / shares	1.10
Options Exercised (in dollars per share) | $ / shares	0.67
Options Cancelled (forfeited) (in dollars per share) | $ / shares	0.62
Options Cancelled (expired) (in dollars per share) | $ / shares	9.68
Balance at the ending of the period (in dollars per share) | $ / shares	$ 0.97