FUTURE ACQUISITION RIGHT AND JOINT DEVELOPMENT AGREEMENT (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Jan. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Business combination, option agreement, purchase price	$ 65,000
Business combination, option agreement, purchase price, percent transfered in cash	20.00%
Business combination, option agreement, purchase price, percent transfered by issuance of equity	80.00%
Business combination, option agreement, share price (in dollars per share)	$ 21.40
Business combination, option agreement, percent of consideration paid in cash if share price falls below share price threshold	100.00%
Business combination, option agreement, weighted average ten day share price, which requires all cash payment (in dollars per share)	$ 19.26
Business combination, option agreement, contingent consideration	$ 25,000
Development milestone payment, period		45 days
Investment		$ 15,000	$ 0
Censa Pharmaceuticals Inc. | CNSA-001 Program | Purchase Provision Terms
Variable Interest Entity [Line Items]
Research and development arrangement, contract to perform for others, compensation earned	17,000
Censa Pharmaceuticals Inc.
Variable Interest Entity [Line Items]
Payments for the option to acquire business	10,000	10,000
Censa Pharmaceuticals, Inc, Equity Holders
Variable Interest Entity [Line Items]
Additional required payments for the option to acquire business, successful development milestones	$ 5,000	$ 5,000