Income taxes (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

The components of income (loss) before income taxes are as follows:

	Years Ended December 31
	2016		2015		2014
Foreign (not subject to income taxes)	$	8,851,332	$	10,502,379	$	10,355,689
Mexico		(3,339,932)		(2,576,885)		(3,591,149)
United States		(3,270,144)		-		-
	$	2,241,256	$	7,925,494	$	6,764,540

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

A reconciliation of the U.S. statutory federal tax rate to the effective benefit rate for the U.S. loss before income taxes for the year ended December 31, 2016 is as follows:

U.S. statutory federal rate	34.0	%
State taxes, net of federal effect	(2.0)	%
Foreign tax rate differential	(128.3)	%
Permanent items	20.9	%
Valuation allowance for deferred tax assets	51.4	%
	(23.9)	%

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

The tax effects of significant items comprising the Company's net long term deferred tax liability at December 31, 2016 were as follows:

Deferred tax assets:
Operating loss carryforwards - Mexico	$	5,545,008
Operating loss carryforwards - United States		150,758
Valuation allowances		(5,695,766)
		-
Deferred tax liabilities:
Property and equipment		129,041
Intangible assets		1,786,200
		1,915,241

Net deferred tax liability	$	1,915,241