INCOME TAXES - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018
Income Taxes [Line Items]
Tax Cuts And Jobs Act Of 2017, change in tax rate, deferred tax asset, provisional income tax expense (benefit)	$ 12,900,000
Accrued interest or penalties related to uncertain tax positions		$ 18,000
Total amount of unrecognized tax benefits		97,000
Federal
Income Taxes [Line Items]
Net operating loss carryforwards		0
Tax credit carryforwards		$ 9,500,000
Federal credit carryforward expiration, beginning period		2019
Federal credit carryforward expiration ending Period		2038
State and local
Income Taxes [Line Items]
Net operating loss carryforwards		$ 52,900,000
Net operating losses expiration beginning period		2028
Tax credit carryforwards		$ 2,300,000
Foreign tax authority | Ireland
Income Taxes [Line Items]
Net operating loss carryforwards		2,400,000
Foreign tax authority | Canada | Research and development
Income Taxes [Line Items]
Tax credit carryforwards		$ 1,600,000