Shareholders' Equity (Details 4)	3 Months Ended
	Mar. 31, 2019 $ / shares shares
Class of Warrant or Right [Line Items]
Warrants outstanding	2,312,165
Warrants outstanding and exercisable	2,312,165
December 31, 2015 [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	4,771	[1]
Exercise price per warrant | $ / shares	$ 7.5	[1]
Warrants outstanding and exercisable	4,771	[1]
November 1, 2016 [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	97,496	[2]
Exercise price per warrant | $ / shares	$ 118.75	[2]
Warrants outstanding and exercisable	97,496	[2]
Warrants term	Nov. 01, 2021	[2]
December 28, 2016 [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	1,908	[3]
Exercise price per warrant | $ / shares	$ 7.5	[3]
Warrants outstanding and exercisable	1,908	[3]
November 20, 2018 [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	1,767,710	[4]
Exercise price per warrant | $ / shares	$ 7.5	[4]
Warrants outstanding and exercisable	1,767,710	[4]
Warrants term	Nov. 20, 2023	[4]
November 20, 2018 [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	106,680	[5]
Exercise price per warrant | $ / shares	$ 9.375	[5]
Warrants outstanding and exercisable	106,680	[5]
Warrants term	Nov. 15, 2023	[5]
November 20, 2018 [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	288,000	[6]
Exercise price per warrant | $ / shares	$ 0.25	[6]
Warrants outstanding and exercisable	288,000	[6]
Warrants term	Nov. 20, 2023	[6]
February 25, 2019 [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	45,600	[7]
Exercise price per warrant | $ / shares	$ 7.1875	[7]
Warrants outstanding and exercisable	45,600	[7]
Warrants term	Feb. 21, 2024	[7]

[1] Represents warrants for ordinary shares issuable upon an exercise price of $7.5 per share, which were granted on December 31, 2015 to Kreos Capital V (Expert) Fund Limited, or Kreos, in connection with a loan made by Kreos to us and are currently exercisable (in whole or in part) until the earlier of (i) December 30, 2025 or (ii) immediately prior to the consummation of a merger, consolidation, or reorganization of us with or into, or the sale or license of all or substantially all the assets or shares of us to, any other entity or person, other than a wholly-owned subsidiary of us, excluding any transaction in which our shareholders prior to the transaction will hold more than 50% of the voting and economic rights of the surviving entity after the transaction. None of these warrants had been exercised as of March 31, 2019.

[2] Represents warrants issued as part of our follow-on offering in November 2016. At any time, the board of directors may reduce the exercise price of the warrants to any amount and for any period of time it deems appropriate.

[3] Represents common warrants that were issued as part of the $8.0 million drawdown under the Loan Agreement which occurred on December 28, 2016. See footnote 1 for exercisability terms.

[4] Represents common warrants that were issued as part of our follow-on offering in November 2018. As of March 31, 2019, warrants to purchase an aggregate 10,666 ordinary shares had been exercised.

[5] Represents common warrants that were issued to the underwriters as compensation for their role in our follow-on offering in November 2018.

[6] Represents pre-funded warrants that were issued as part of our follow-on offering in November 2018. As of March 31, 2019, pre-funded warrants to purchase an aggregate 762,372 ordinary shares had been exercised.

[7] Represents warrants that were issued to the exclusive placement agent and its designees as compensation for their role in our follow-on offering in February 2019.