Senior Convertible Bonds (Narrative) (Details)		1 Months Ended		12 Months Ended
	Oct. 21, 2015 $ / shares	May 02, 2018 $ / shares shares	May 02, 2017 $ / shares shares	Dec. 31, 2018 USD ($) Bonds shares	Dec. 31, 2017 USD ($) Bonds $ / shares shares	Dec. 31, 2016 USD ($) Bonds shares	May 02, 2016 USD ($)
Senior Convertible Bonds (Textual)
Debt discount on derivative liability				$ 993,000	$ 1,267,000
Interest expense				0	0	$ 231,000
Convertible bonds				3,470,000	3,470,000	3,470,000
Principal amount				3,266,700	3,358,900
Debt discount amortization, net				$ 993,000	$ 1,267,000	1,513,000
Average Zion stock price | $ / shares		$ 4.68	$ 1.196
Stock issued to bondholders | shares		70,780	289,213
Right offering [Member]
Senior Convertible Bonds (Textual)
Debt instrument, maturity date	May 02, 2021
Convertible bonds purchase price | $ / shares	$ 100
Senior unsecured notes interest rate	10.00%
Debt conversion, description				Under the rights offering, the Company distributed at no cost, 360,000 non-transferable subscription rights to subscribe for, on a per right basis, two 10% Convertible Senior Bonds par $100 due May 2, 2021 (the "Notes due May 2021"), to persons who owned shares of the Company's Common Stock on October 15, 2015, the record date for the offering. Each whole subscription right entitled the participant to purchase two convertible bonds at a purchase price of $100 per bond.
Principal amount							$ 3,470,000
10% Senior Convertible Bonds [Member]
Senior Convertible Bonds (Textual)
Debt instrument, maturity date				May 02, 2021
Debt instrument payment description				Payable annually in arrears on May 2 of each year, commencing May 2, 2017.
Debt discount on derivative liability				$ 1,626,000
Senior unsecured notes interest rate		10.00%	10.00%		10.00%
Debt conversion, description				At any time prior to the close of business on the business day immediately preceding April 2, 2021, holders may convert their notes into Common Stock at the conversion rate of 44 shares per $100 bond (which is equivalent to a conversion rate of approximately $2.27 per share).
Amortization expense				$ 27,000	$ 28,000	18,000
Convertible bonds				1,844,000
Principal amount				3,470,000
Debt discount amortization, net				$ 274,000	$ 246,000	113,000
10% Senior Convertible Bonds [Member] | Right offering [Member]
Senior Convertible Bonds (Textual)
Debt instrument, maturity date				May 02, 2021
Debt instrument payment description				The number of shares for the payment of interest in shares of Common Stock, in lieu of the cash amount, will be based on the average of the closing prices of the Company's Common Stock as reported by Bloomberg L.P. for the 30 trading days preceding the record date for the payment of interest; such record date has been designated and will always be the 10th business day prior to the interest payment date on May 2 of each year. The number of shares for the payment of principal, in lieu of the cash amount, shall be based upon the average of the closing price of the Company's Common Stock as reported by Bloomberg L.P. for the 30 trading days preceding the principal repayment date; such record date has been designated as the trading day immediately prior to the 30-day period preceding the maturity date of May 2, 2021.
Description of note redemption				The Company was entitled to redeem for cash the outstanding Notes at an amount equal to the principal and accrued and unpaid interest, plus a 10% premium.
Senior unsecured notes interest rate			10.00%
10% Senior Convertible Bonds [Member] | Debt issuance [Member]
Senior Convertible Bonds (Textual)
Debt instrument payment description				The interest was paid-in-kind ("PIK") in the form of Common Stock. An average Zion stock price of $1.196 was determined based on the 30 trading days prior to the record date of April 18, 2017. This figure was used to divide into 10% of the par value of the bonds held by the holders.
10% Senior Convertible Bonds [Member] | Debt issuance [Member] | Right offering [Member]
Senior Convertible Bonds (Textual)
Convertible bonds purchase price | $ / shares					$ 2.27
Interest expense				$ 331,000	$ 346,000	$ 0
Number of convertible bonds | Bonds				922	982	129
Convertible bond price					$ 100
Common stock issued | shares				41,000	43,000	5,700
Financial expense (income)				$ 84,000	$ 52,000	$ (5,000)