SUBSEQUENT EVENTS (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended
	Jul. 23, 2018	Oct. 19, 2017
Maximum [Member]
Additional AmountPayable For Achievement Of Regulatory And Commercial Milestones		$ 320.0
Maximum [Member] | Subsequent Event [Member]
Additional AmountPayable For Achievement Of Regulatory And Commercial Milestones	$ 760.0
Chiesi Agreement [Member]
Upfront Nonrefundable Noncreditable Payment Receivable		25.0
Additional Amounts Payable To Cover Development Costs		25.0
Maximum Entitlement Of Development Costs To Cover Per Year		$ 10.0
Chiesi Agreement [Member] | Subsequent Event [Member]
Upfront Nonrefundable Noncreditable Payment Receivable	25.0
Additional Amounts Payable To Cover Development Costs	20.0
Maximum Entitlement Of Development Costs To Cover Per Year	$ 7.5
Chiesi Agreement [Member] | Maximum [Member]
Payment On Net Sales Percentage		35.00%
Chiesi Agreement [Member] | Maximum [Member] | Subsequent Event [Member]
Payment On Net Sales Percentage	40.00%
Chiesi Agreement [Member] | Minimum [Member]
Payment On Net Sales Percentage		15.00%
Chiesi Agreement [Member] | Minimum [Member] | Subsequent Event [Member]
Payment On Net Sales Percentage	15.00%