Commitments and Contingent Liabilities - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 28, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
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		$ 3,474	$ 2,748	$ 2,194
Pledged bank deposits		1,038	807
Operating Lease Commitments		$ 1,202	$ 955
Settlement agreement date		February 2015
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 2020
Maximum
Loss Contingencies [Line Items]
Operating lease agreements, expiration year		2024
Maximum | Motor Vehicles
Loss Contingencies [Line Items]
Operating lease agreements, expiration year		2020