Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2018

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of warrants and options exercise prices and expiration dates

	Exercise Price			Number of Shares		Expiration Date	Warrants or Options
	US$
To non-employees
		0.01			10,000	October 01, 2027	Options
		0.01			45,000	February 28, 2028	Options
		0.01			30,000	January 01, 2028	Options
		1.67			105,000	October 01, 2024	Options
		1.70			115,000	December 20, 2022	Options
		2.61			77,000	December 04, 2021	Options
To employees and directors
		0.01			15,000	November 11, 2023	Options
		0.01			15,000	March 31, 2024	Options
		0.01			5,000	June 11, 2024	Options
		0.01			10,000	September 30, 2025	Options
		0.01			25,000	December 31, 2025	Options
		0.01			305,000	June 05, 2026	Options
		0.01			25,000	December 31, 2026	Options
		0.01			500,000	January 01, 2027	Options
		0.01			10,000	January 04, 2027	Options
		0.01			60,000	April 17, 2027	Options
		0.01			30,000	October 01, 2027	Options
		0.01			202,500	January 01, 2028	Options
		0.01			110,000	January 04, 2028	Options
		0.01			6,000	April 06, 2028	Options
		1.33			25,000	May 01, 2023	Options
		1.38			108,000	January 02, 2021	Options
		1.38			123,057	January 02, 2025	Options
		1.55			400,000	June 05, 2022	Options
		1.67			340,000	October 01, 2020	Options
		1.67			343,886	October 01, 2024	Options
		1.70			168,500	December 20, 2022	Options
		1.73			25,000	January 09, 2019	Options
		1.75			400,000	June 07, 2023	Options
		1.78			25,000	September 04, 2024	Options
		1.87			25,000	January 31, 2022	Options
		1.95			25,000	April 02, 2020	Options
		1.96			25,000	September 3, 2019	Options
		2.03			25,000	May 01, 2021	Options
		2.31			400,000	January 01, 2024	Options
		2.61			604,500	December 04, 2021	Options
		4.15			25,000	July 02, 2024	Options
To investors
		1.00			243,853	May 02, 2020	Warrants
		1.00			546,050	October 29, 2020	Warrants
		1.00			2,144,510	March 03, 2020	Warrants
		1.00			359,610	August 14, 2020	Warrants
		1.00			240,578	January 08, 2021	Warrants
		2.00			1,498,804	January 31, 2020	Warrants
		3.00			640,735	June 29, 2020	Warrants
		5.00			372,400	April 19, 2020	Warrants
Total outstanding		1.56	*		10,834,983

* Weighted Average

Schedule of warrant and option transactions

	Number of shares			Weighted Average exercise price
				US$
Outstanding, December 31, 2015		3,629,693			1.76
Changes during 2016 to:
Granted to employees, officers, directors and others		2,265,000			0.27
Expired/Cancelled/Forfeited		(172,250	)		2.76
Exercised		(1,555,500	)		0.01
Outstanding, December 31, 2016		4,166,943			1.58
Changes during 2017 to:
Granted to employees, officers, directors and others		2,212,500			0.34
Expired/Cancelled/Forfeited		(360,000	)		2.32
Exercised		(1,680,000	)		0.33
Outstanding, December 31, 2017		4,339,443			1.37
Changes during 2018 to:
Granted to employees, officers, directors and others*		969,000			1.11
Expired/Cancelled/Forfeited		(237,500	)		1.75
Exercised		(282,500	)		0.07
Outstanding, December 31, 2018		4,788,443			1.37
Exercisable, December 31, 2018		4,778,443			1.38

* The receipt of a stock option grant by the grantee recipient is a non-taxable event according to the Internal Revenue Service. The grantee who later chooses to exercise penny stock options must recognize the market value in income in the year of exercise.

Schedule of stock warrants and options outstanding

Shares underlying outstanding options (non-vested)								Shares underlying outstanding options (fully vested)
Range of exercise price		Number outstanding		Weighted average remaining contractual life (years)		Weighted Average Exercise price		Range of exercise price		Number Outstanding		Weighted average remaining contractual life (years)		Weighted Average Exercise price
US$						US$		US$						US$
	—		—		—		—		0.01		15,000		4.87		0.01
	—		—		—		—		0.01		15,000		5.25		0.01
	—		—		—		—		0.01		5,000		5.45		0.01
	—		—		—		—		0.01		10,000		6.75		0.01
	—		—		—		—		0.01		25,000		7.00		0.01
	—		—		—		—		0.01		305,000		7.42		0.01
	—		—		—		—		0.01		525,000		8.00		0.01
	—		—		—		—		0.01		10,000		8.01		0.01
	—		—		—		—		0.01		60,000		8.29		0.01
	0.01		10,000		8.75		0.01		0.01		30,000		8.75		0.01
	—		—		—		—		0.01		232,500		9.00		0.01
	—		—		—		—		0.01		110,000		9.01		0.01
	—		—		—		—		0.01		45,000		9.16		0.01
	—		—		—		—		0.01		6,000		9.26		0.01
	—		—		—		—		1.33		25,000		4.32		1.38
	—		—		—		—		1.38		108,000		2.01		1.38
	—		—		—		—		1.38		123,057		6.01		1.38
	—		—		—		—		1.55		400,000		3.43		1.38
	—		—		—		—		1.67		340,000		1.75		1.67
	—		—		—		—		1.67		448,886		5.76		1.67
	—		—		—		—		1.70		298,500		3.97		1.70
	—		—		—		—		1.73		25,000		0.02		1.73
	—		—		—		—		1.75		400,000		4.52		1.70
	—		—		—		—		1.87		25,000		3.09		1.87
	—		—		—		—		1.95		25,000		1.25		1.95
	—		—		—		—		1.96		25,000		0.67		1.96
	—		—		—		—		2.03		25,000		2.33		2.03
	—		—		—		—		2.31		400,000		5.01		2.31
									2.61		681,500		2.93		2.61
	—		—		—		—		4.15		25,000		5.51		4.15
	0.01		10,000				0.01		0.01-4.15		4,778,443				1.38

Schedule of warrants description

	Period of Grant	US$		Expiration Date
ZNWAA Warrants	March 2013 – December 2014		2.00	January 31, 2020
ZNWAD Warrants**	January 2015 – March 2016		1.00	May 02, 2020
ZNWAE Warrants	November 2016 – March 2017		1.00	May 01, 2020
ZNWAF Warrants**	May 2017 – July 2017		1.00	August 14, 2020
ZNWAG Warrants	October 2017 – December 2017		1.00	January 08, 2021
ZNWAH Warrants**	February 2018		5.00	April 2, 2020
ZNWAI Warrants**	April 2018 – May 2018		3.00	June 29, 2020
ZNWAJ Warrants	August 2018 – September 2018		1.00	October 29, 2020
ZNWAK Warrants	December 2018 – January 2019		0.01	February 25, 2020

*	Zion’s ZNWAB Warrants expired on May 2, 2017 and its ZNWAC Warrants expired on May 2, 2018
**	On December 4, 2018, the Company extended the termination date of the Warrants by one (1) year.

Dividend Reinvestment and Stock Purchase Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of warrants description

Change during 2016 to:

	ZNWAA		ZNWAB			ZNWAC			ZNWAD			ZNWAE		ZNWAF		ZNWAG		ZNWAH		ZNWAI		ZNWAJ		Total
Outstanding warrants, December 31, 2015		1,567,155		287,072			287,072			287,072			-		-		-		-		-		-		2,428,371
Exercise Price	$	2.00	$	1.00		$	1.00		$	1.00		$	1.00	$	1.00	$	1.00	$	5.00	$	3.00	$	1.00
Warrant Termination Date		1/31/2020		5/2/2017			5/2/2018			5/2/2020			5/2/2020		8/14/2020		1/8/2021		4/19/2020		6/29/2020		10/29/2020
Change during 2016 to:
Issued		-		95,180			95,180			95,180			803,376		-		-		-		-		-		1,088,916
Exercised		-		(68,698	)		(37,524	)		(34,412	)		-		-		-		-		-		-		(140,634	)
Expired		-		-			-			-			-		-		-		-		-		-		-
Outstanding and exercisable warrants, December 31, 2016		1,567,155		313,554			344,728			347,840			803,376		-		-		-		-		-		3,376,653

Change during 2017 to:

	ZNWAA		ZNWAB		ZNWAC		ZNWAD		ZNWAE		ZNWAF		ZNWAG	ZNWAH	ZNWAI	ZNWAJ	Total
Issued	-		-		-		-		3,262,742		683,865		414,300	-	-	-	4,360,907
Exercised	(42,538	)	(206,737	)	(69,576	)	(53,506	)	(1,037,999	)	(223,634	)	-	-	-	-	(1,633,990	)
Expired	-		(106,817	)	-		-		-		-		-	-	-	-	(106,817	)
Outstanding and exercisable warrants, December 31, 2017	1,524,617		-		275,152		294,334		3,028,119		460,231		414,300	-	-	-	5,996,753

Change during 2018 to:

	ZNWAA			ZNWAB		ZNWAC			ZNWAD			ZNWAE			ZNWAF			ZNWAG			ZNWAH			ZNWAI			ZNWAJ			Total
Issued		-			-		-			-			10,493			100			6,030			373,900			656,274			550,900			1,597,697
Exercised		(25,813	)		-		(196,913	)		(50,481	)		(894,102	)		(100,721	)		(179,752	)		(1,500	)		(15,539	)		(4,850	)		(1,469,671	)
Expired		-			-		(78,239	)		-			-			-			-			-			-			-			(78,239	)
Outstanding and exercisable warrants, December 31, 2018		1,498,804			-		-			243,853			2,144,510			359,610			240,578			372,400			640,735			546,050			6,046,540

Non Employees [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of assumptions used to estimate fair value of warrants granted using black-scholes option pricing model

	For the year ended  December 31,
	2018		2017		2016
Weighted-average fair value of underlying stock at grant date	$	3.37	$	1.56	$	1.51
Dividend yields		—		—		—
Expected volatility		73%-76%		68%-72%		69%-70%
Risk-free interest rates		2.46%-2.81%		2.36%-2.44%		1.73%-1.83%
Expected lives (in years)		10.00		10.00		10.00
Weighted-average grant date fair value	$	3.36	$	1.55	$	1.50

Non Employees [Member] | Warrants and Options [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of compensation cost of warrant and option issuances

For the year ended December 31,
2018		2017		2016
US$		US$		US$
	302,000		276,000		360,000

Employees and Directors [Member] | Warrants and Options [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of compensation cost of warrant and option issuances

For the year ended December 31,
2018		2017		2016
US$		US$		US$
	1,553,000		2,448,000		2,726,000

Employees [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of assumptions used to estimate fair value of warrants granted using black-scholes option pricing model

	For the year ended December 31,
	2018			2017			2016
Weighted-average fair value of underlying stock at grant date	$	2.38		$	1.48		$	1.56
Dividend yields		—			—			—
Expected volatility		68%-87	%		45%-69	%		57%-69%
Risk-free interest rates		2.01%-2.74	%		1.45%-1.94	%		0.94%-1.93%
Expected lives (in years)		3.00-5.50			3.00-5.87			3.00-5.50
Weighted-average grant date fair value	$	1.72		$	1.23		$	1.35

Employees [Member] | Warrants and Options [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of compensation cost of warrant and option issuances

For the year ended December 31,
2018		2017		2016
US$		US$		US$
	348,000		256,000		213,000