INCOME TAXES- Summary of Expected Tax Expense (Benefit) Based on the U.S. Federal Statutory Rate is Reconciled with the Actual Tax Provision (Benefit) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
INCOME TAXES
U. S. federal statutory rate	$ (4,500,000)	$ (31,071,000)
State taxes, net of federal benefit	(600,000)	$ (1,383,000)
Tax rate change	$ 665,000
U. S. federal statutory rate, Percent	21.00%	21.00%
State taxes, net of federal benefit, Percent	2.80%	0.93%
Tax rate change, Percent	(3.10%)	0.00%
Permanent differences
Permanent differences-- Non-deductible write-off of acquired R&D expenses		$ 24,369,000
Permanent differences- Change in fair value of derivative liabilities	$ (4,000)	8,000
Permanent differences- Other permanent differences	32,000	4,000
Change in valuation allowance	4,681,000	$ 8,073,000
Other	$ (274,000)
Permanent differences-- Non-deductible write-off of acquired R&D expenses, Percent	0.00%	(16.47%)
Permanent differences- Change in fair value of derivative liabilities, Pecent	0.02%	(0.01%)
Permanent differences- Other permanent differences, Percent	(0.15%)	0.00%
Change in valuation allowance, Percent	(21.85%)	(5.46%)
Other, Percent	1.28%	0.00%
Income tax provision (benefit), Percent	0.00%	0.00%