Income taxes (Tables)

12 Months Ended

Dec. 31, 2017

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

The components of income (loss) before income taxes for the years ended December 31 are as follows:

	Year Ended December 31,
	2017		2016		2015
Foreign (not subject to income taxes)	$	10,041,971	$	8,851,332	$	10,502,379
Mexico		(3,188,134)		(3,339,932)		(2,576,885)
United States		(2,010,241)		(3,270,144)		-
	$	4,843,596	$	2,241,256	$	7,925,494

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

The Company's provision for income taxes for the years ended December 31, 2017 and 2016 consisted of a deferred tax benefit relating to U.S. operations made up of the following:

	Year Ended December 31,
	2017		2016
Current tax expense	$	1,371	$	-
Deferred tax benefit		(890,348)		(536,057)
	$	(888,977)	$	(536,057)

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 years ended December 31, 2017 and 2016 is as follows:

	Year Ended December 31,
	2017			2016
U.S. statutory federal rate		34.00	%		34.00	%
State taxes, net of federal effect		2.00			(2.00)
Foreign tax rate differential		(82.91)			(128.30)
R&D tax credit		(2.49)			0.00
Permanent items		13.39			20.90
Tax Act adjustment		(11.25)			0.00
Valuation allowance for deferred tax assets		28.90			51.40
		(18.36)	%		(24.00)	%

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, 2017 and 2016 were as follows:

	December 31,
	2017		2016
Deferred tax assets:
Operating loss carryforwards - Mexico	$	4,923,026	$	4,462,746
Land basis difference		702,547		414,101
Start-up costs		747,215		668,161
Operating loss carryforwards - United States		-		150,758
Valuation allowances		(6,372,788)		(5,695,766)
		-		-
Deferred tax liabilities:
Property and equipment		205,827		129,041
Intangible assets		819,066		1,786,200
		1,024,893		1,915,241

Net deferred tax liability	$	1,024,893	$	1,915,241