8. Share-based payments (Details 9) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Outstanding, Beginning	14,421,379	14,421,379
Outstanding, Ending	14,467,717	14,421,379
Exercisable, Ending	14,467,717	14,421,379
Weighted Average Exercise Price per Share
Outstanding, Beginning	$ 0.02	$ 0.02
Outstanding, Ending	0.05	0.02
Exercisable, Ending	$ 0.05	$ 0.02
Weighted-average Remaining Life (Years)
Outstanding	1 year 6 months	2 years 6 months
Exercisable	4 years 7 months 6 days	1 year 6 months
Aggregate Intrinsic Value
Outstanding, Ending	$ 1,564	$ 725,950
Exercisable, Ending	$ 1,564	$ 725,950
Employee stock options Fully-vested upon grant [Member]
Number of Shares
Outstanding, Beginning	4,000,000	4,000,000
Outstanding, Ending	4,000,000	4,000,000
Exercisable, Ending	4,000,000	4,000,000
Weighted Average Exercise Price per Share
Outstanding, Beginning	$ 2.00	$ 2.00
Outstanding, Ending	2.00	2.00
Exercisable, Ending	$ 2.00	$ 2.00
Weighted-average Remaining Life (Years)
Outstanding	0 years	0 years
Exercisable	0 years	0 years
Aggregate Intrinsic Value
Outstanding, Ending
Exercisable, Ending

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Intrinsic value of equity-based compensation awards outstanding. Excludes stock and unit options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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