Commitments and Contingent Liabilities - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	Sep. 10, 2018	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Operating lease expiration description				The facilities of the Company are leased under various operating lease agreements for periods ending no later than 2024.
Lease and rental expense				$ 4,033	$ 3,474	$ 2,748
Pledged bank deposits		$ 1,143		1,143	1,038
Operating Lease Commitments		1,299		1,299	$ 1,202
Settlement agreement date			February 10, 2015
License and Collaboration Agreement (the “Zai Agreement”)
Loss Contingencies [Line Items]
Non-refundable up-front license fee, amount	$ 15,000
License fees received		$ 12,700
License and Collaboration Agreement (the “Zai Agreement”) | License | Accounting Standards Update 2014-09
Loss Contingencies [Line Items]
Liability, revenue recognized				767
Settlement Agreement
Loss Contingencies [Line Items]
Settlement expense			$ 5,500
Net sales milestone				$ 250,000
Motor Vehicles
Loss Contingencies [Line Items]
Operating lease expiration description				The Company also leases motor vehicles under various operating leases, which expire on various dates, the latest of which is in 2021.
Maximum
Loss Contingencies [Line Items]
Operating lease agreements, expiration year				2024
Maximum | License and Collaboration Agreement (the “Zai Agreement”)
Loss Contingencies [Line Items]
Regulatory and commercial milestone payments	$ 78,000
Maximum | Motor Vehicles
Loss Contingencies [Line Items]
Operating lease agreements, expiration year				2021
Minimum | License and Collaboration Agreement (the “Zai Agreement”) | License
Loss Contingencies [Line Items]
Percentage of tiered royalties rates on net sales	10.00%