DESCRIPTION OF THE BUSINESS AND MERGER TRANSACTION - Summary of Significant Sources and Uses of Cash Related to Closing of Merger Transaction (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	May 31, 2021	Mar. 31, 2021
Business Description And Reverse Recapitalization [Abstract]
Cash at Megalith		$ 27,669
Cash from PIPE (private investment in public entity) investors		20,003
Total sources of cash		47,672
Cash paid to underwriters and other transaction costs		(3,987)
Cash paid to Customers Bank as consideration		(23,125)
Cash from recapitalization transaction		20,560
Cash proceeds used to pay down BMT debt		(8,834)
Cash proceeds received by BMT and used to pay down debt		(6,738)
Total cash used to pay down outstanding debt		(15,572)
Net cash proceeds received by BMT from the reverse recapitalization transaction		4,988
90 day merger true-up, accrued by BMT at March 31, 2021		(3,672)
Final cash to BMT from the reverse recapitalization transaction		$ 1,316
Forecast
Schedule Of Reverse Recapitalization [Line Items]
Payment for 90 day merger true-up	$ 3,700