Significant Accounting Policies - Property and Equipment at Cost Using Straight-Line Method (Details)	12 Months Ended
	Dec. 31, 2017
Computers and laboratory equipment | Minimum
Property Plant And Equipment [Line Items]
Straight line depreciation rate	15.00%
Computers and laboratory equipment | Maximum
Property Plant And Equipment [Line Items]
Straight line depreciation rate	33.00%
Office furniture | Minimum
Property Plant And Equipment [Line Items]
Straight line depreciation rate	6.00%
Office furniture | Maximum
Property Plant And Equipment [Line Items]
Straight line depreciation rate	33.00%
Production equipment
Property Plant And Equipment [Line Items]
Straight line depreciation rate	20.00%
Leasehold improvements
Property Plant And Equipment [Line Items]
Straight line depreciation useful life	Over the shorter of the term of the lease or its useful life