Concentration of credit risk (Details) - USD ($)

3 Months Ended

Sep. 30, 2019

Jun. 30, 2019

Sep. 30, 2018

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

Concentration of Credit Risk

Credit Risk

Financial Instruments, which potentially subject the Company to concentration of credit risk, consist principally of cash and cash equivalents, restricted cash and trade receivables. Concentration of credit risk with respect to trade receivables is generally diversified due to the large number of entities comprising the Company's customer base and their dispersion across geographic areas principally within the United States and international. The Company routinely address the financial strength of its customer and, as a consequence, believes that its receivable credit risk exposure is limited. The Company does not require customers to post collateral.

Major Customer

One customer accounted for more than 10% of net sales during the three months ended September 30, 2019. No customer accounted for more than 10% of net sales during the three months ended September 30, 2018.

As of September 30, 2019 the Company had one customer that represents more than 10% of the total accounts receivable balance. As of June 30, 2019 the Company had no customer that represents more than 10% of the total accounts receivable balance.

Major Supplier

The Company's two largest suppliers accounted for 15% and 25% of the total purchase for the three-month period ended September 30, 2019. The Company's two largest suppliers accounted for of total purchases for more than 12% and 24% of total purchase for the three-month period ended September 30, 2018.

Foreign Sales

Domestic and international sales from continuing operations are as follows: