STOCKHOLDERS' EQUITY - JonesTrading Agreements (Details) - USD ($) $ in Millions			9 Months Ended
	Sep. 30, 2020	Aug. 14, 2020	Sep. 30, 2020
Class of Stock [Line Items]
Noncash Or Part Noncash Acquisition, Proceeds From Sale Of Common Stock Included In Accounts Receivable			$ 2.8
Sale of Stock, Number of Shares Issued in Transaction		2,415,000
Common Stock, Aggregate Offering Price	$ 150.0
At-The-Market Agreement [Member] | JonesTrading Institutional Services LLC [Member]
Class of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction			415,904