7. FINANCIAL INSTRUMENTS - Change in contingent consideration (Details) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Changes in fair value of contingent consideration
Contingent consideration, beginning of period	$ 3,898	$ 4,206
Change due to accretion	24	29
Contingent consideration, end of period	$ 3,922	$ 4,235

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant