Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Details 3) - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning of year		79,890	134,150
Granted		147,088
Exercised
Expired/cancelled		(149,588)	(54,260)
Outstanding, end of year		77,390	79,890
Exercisable, end of year		77,390
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning of year		$ 94.51	$ 85.22
Granted		0.98
Exercised
Expired/cancelled		(0.98)	(91.43)
Outstanding, end of year		95.27	$ 94.51
Exercisable, end of year		$ 95.27
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Life [Roll Forward]
Outstanding, beginning of year		3 years 3 months 18 days	4 years 3 months 18 days
Granted		9 years 6 months
Exercised
Expired/cancelled
Outstanding, end of year		3 years 3 months 18 days	3 years 3 months 18 days
Exercisable, end of year		3 years 3 months 18 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Aggregate Intrinsic Value [Roll Forward]
Outstanding. beginning of year	[1]
Granted	[1]
Exercised	[1]
Expired/cancelled	[1]
Outstanding. ending of year	[1]
Exercisable, end of year	[1]

[1] The aggregate intrinsic value represents the total intrinsic value (the difference between the deemed fair value of the Company's Ordinary Shares on the last day of 2018 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2018. This amount is impacted by the changes in the fair value of the Company's shares.