14. ACQUISITION (Details)		3 Months Ended			12 Months Ended
	Nov. 23, 2015 USD ($) patent	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)
Acquisition disclosure
Discount rate					0.148
Other accrued expenses
Acquisition disclosure
Contingent consideration liability					$ 3,900,000	$ 3,700,000
Accrued expenses and other liabilities
Acquisition disclosure
Contingent consideration liability					0	492,000
MikaMonu
Acquisition disclosure
Cash paid for acquisition	$ 4,900,000
Payment of escrow deposit		$ 1,000,000	$ 750,000	$ 743,000
Potential cash retention payments	$ 2,500,000
Discount rate (as a percent)	14.8
Change in contingent consideration liability					80,000	(326,000)	$ (466,000)
MikaMonu | Other accrued expenses
Acquisition disclosure
Contingent consideration liability	$ 5,800,000				3,900,000	3,700,000
MikaMonu | Accrued expenses and other liabilities
Acquisition disclosure
Contingent consideration liability					0	$ 492,000
MikaMonu | United States
Acquisition disclosure
Number of patents held | patent	12
MikaMonu | Continued employment of Dr. Avidan Akerib
Acquisition disclosure
Amount of payment held in escrow	$ 2,500,000
Contingent consideration	1,200,000
MikaMonu | Product development milestones and revenue targets
Acquisition disclosure
Contingent consideration					1,300,000
MikaMonu | Product development milestones and revenue targets | Maximum
Acquisition disclosure
Contingent consideration					38,800,000
MikaMonu | Product development milestones and revenue targets | Accrued expenses and other liabilities
Acquisition disclosure
Contingent consideration					$ 750,000
MikaMonu | Revenue milestones to be achieved by January, 1 2021
Acquisition disclosure
Contingent consideration	2,800,000
MikaMonu | Revenue milestones to be achieved by January, 1 2022
Acquisition disclosure
Contingent consideration	4,000,000
MikaMonu | Quarterly payments based on net revenue | Maximum
Acquisition disclosure
Contingent consideration	$ 30,000,000
Contingent consideration, percent of net revenue	5.00%