COMMON STOCKHOLDERS' EQUITY (Details) - USD ($)			12 Months Ended
	Oct. 31, 2019	Jan. 01, 2019	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued (in shares)			50,333,655	48,532,199
Issuance of common stock, related expenses			$ 4,400,000	$ 6,500,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares issued (in shares)			43,332	35,281
Percent of market value discount		90.00%
Maximum payroll deduction		10.00%
Maximum number of shares per employee (in shares)		2,000
Maximum value of shares per employee		$ 25,000
Issuance of common stock, related expenses			$ 200,000
Equity Distribution Agreement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity distribution period	3 years
Common stock, shares, sold (in shares)			1,710,779	381,105
Proceeds from sale of common stock			$ 81,800,000	$ 19,300,000
Payments for commissions			800,000	200,000
Equity issuance costs			$ 100,000	$ 500,000
Maximum | Equity Distribution Agreement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of common stock, gross sales price	$ 300,000,000.0