SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended	12 Months Ended
	Jul. 23, 2018	Oct. 19, 2017	Oct. 31, 2015	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Dec. 31, 2016
Significant Accounting Policies [Line Items]
Common Stock, Par or Stated Value Per Share					$ 0.001	$ 0.001
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount					7,838,120	7,458,380	7,684,820
Retained Earnings (Accumulated Deficit)					$ (340,829)	$ (322,553)
Cash and Cash Equivalents, at Carrying Value					$ 17,792	37,808	$ 51,163		$ 63,281
Tax Rate Assumption Related To Deferred Tax Difference Reversal					The Company used statutory tax rates of 27% and 23%.
Incremental average borrowing rate at inception					12.58%
Operating Lease, Right-of-Use Asset					$ 5,677	$ 0		$ 5,900
Operating Lease, Liability					5,667			$ 5,700
2021 Notes [Member]
Significant Accounting Policies [Line Items]
Long-term Debt, Gross					$ 57,900
Amended Pfizer Agreement [Member] | Protalix Bio Therapeutics Incorporation [Member] | Brazil [Member]
Significant Accounting Policies [Line Items]
Collaborative Arrangement Revenues and Expenses Sharing Percentage			100.00%
Chiesi US Agreement [Member]
Significant Accounting Policies [Line Items]
Upfront Nonrefundable Non-Creditable Payment Receivable	$ 25,000	$ 25,000
Additional Amounts Payable To Cover Development Costs	20,000
Maximum Entitlement Of Development Costs To Cover Per Year	7,500
Additional Amount Payable For Achievement Of Regulatory And Commercial Milestones	$ 760,000
Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Modification of Contract				$ 6,200
Chiesi US Agreement [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Payment On Net Sales Percentage	15.00%
Chiesi US Agreement [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Payment On Net Sales Percentage	40.00%
Chiesi Ex US Agreement [Member]
Significant Accounting Policies [Line Items]
Upfront Nonrefundable Non-Creditable Payment Receivable		25,000
Additional Amounts Payable To Cover Development Costs		25,000
Maximum Entitlement Of Development Costs To Cover Per Year		10,000
Additional Amount Payable For Achievement Of Regulatory And Commercial Milestones		$ 320,000
Chiesi Ex US Agreement [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Payment On Net Sales Percentage		15.00%
Chiesi Ex US Agreement [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Payment On Net Sales Percentage		35.00%