Concentration of credit risk (Tables)

3 Months Ended

Sep. 30, 2020

Concentration of credit risks [Abstract]

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

Domestic and international sales from continuing operations are as follows:

( in thousands)	For the Three Months Ended December 31,								For the Six Months Ended December 31,
	2020				2019				2020				2019
Domestic	$	1,865	64.4	%	$	1,590	58.0	%	$	3,408	64.2	%	$	3,056	60.8	%
Foreign	1,033		35.6	%	1,150		42.0	%	1,904		35.8	%	1,972		39.2	%
Total	$	2,898	100.0	%	$	2,740	100.0	%	$	5,312	100.0	%	$	5,028	100.0	%