Stockholders' Equity (Details 4)	6 Months Ended
	Jun. 30, 2019 $ / shares
ZNWAD Warrants [Member]
Class of Warrant or Right [Line Items]
Exercise Price	$ 1.00
Investor [Member] | ZNWAA Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAA Warrants	[1],[2]
Exercise Price	$ 2.00	[1],[2]
Expiration Date	Jan. 31, 2021	[1],[2]
Investor [Member] | ZNWAA Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Mar. 03, 2013	[1],[2]
Investor [Member] | ZNWAA Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Dec. 31, 2014	[1],[2]
Investor [Member] | ZNWAD Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAD Warrants	[1],[2],[3]
Exercise Price	$ 1.00	[2]
Expiration Date	May 02, 2021
Investor [Member] | ZNWAD Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Jan. 01, 2015	[1],[2],[3]
Investor [Member] | ZNWAD Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Mar. 31, 2016	[1],[2],[3]
Investor [Member] | ZNWAE Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAE Warrants	[1],[2]
Exercise Price	$ 1.00	[2]
Expiration Date	May 01, 2021	[1],[2]
Investor [Member] | ZNWAE Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Nov. 01, 2016	[2],[3]
Investor [Member] | ZNWAE Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Mar. 31, 2017	[2],[3]
Investor [Member] | ZNWAF Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAF Warrants	[1],[2],[3]
Exercise Price	$ 1.00	[1],[2],[3]
Expiration Date	Aug. 14, 2021	[1],[2],[3]
Investor [Member] | ZNWAF Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	May 01, 2017	[1],[2],[3]
Investor [Member] | ZNWAF Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Jul. 31, 2017
Investor [Member] | ZNWAG Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAG Warrants	[2]
Exercise Price	$ 1.00	[2]
Expiration Date	Jan. 08, 2021	[2]
Investor [Member] | ZNWAG Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Oct. 01, 2017	[2]
Investor [Member] | ZNWAG Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Dec. 31, 2017	[2]
Investor [Member] | ZNWAH Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAH Warrants	[1],[2],[3]
Period of Grant	Feb. 28, 2018	[1],[2],[3]
Exercise Price	$ 5.00	[1],[2],[3]
Expiration Date	Apr. 02, 2021	[1],[2],[3]
Investor [Member] | ZNWAI Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAI Warrants	[1],[2],[3]
Exercise Price	$ 3.00	[1],[2],[3]
Expiration Date	Feb. 28, 2018	[1],[2],[3]
Investor [Member] | ZNWAI Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Apr. 01, 2018	[1],[2],[3]
Investor [Member] | ZNWAI Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	May 31, 2018
Investor [Member] | ZNWAJ Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAJ Warrants	[1],[2]
Exercise Price	$ 1.00	[1],[2]
Expiration Date	Oct. 29, 2021	[1],[2]
Investor [Member] | ZNWAJ Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Aug. 31, 2018	[1],[2]
Investor [Member] | ZNWAJ Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Sep. 30, 2018	[1],[2]
Investor [Member] | ZNWAK Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAK Warrants	[1],[2]
Exercise Price	$ 0.01	[1],[2]
Expiration Date	Feb. 25, 2021
Investor [Member] | ZNWAK Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Dec. 01, 2018	[1],[2]
Investor [Member] | ZNWAK Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Jan. 31, 2019	[1],[2]
Investor [Member] | ZNWAL Warrants [Member]
Class of Warrant or Right [Line Items]
Name	ZNWAL Warrants	[2]
Exercise Price	$ 2.00	[2]
Expiration Date	Aug. 26, 2021	[2]
Investor [Member] | ZNWAL Warrants [Member] | Beginning Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Jul. 01, 2019	[2]
Investor [Member] | ZNWAL Warrants [Member] | Ending Date [Member]
Class of Warrant or Right [Line Items]
Period of Grant	Aug. 31, 2019	[2]

[1] On May 29, 2019, the Company extended the termination date of the Warrants by one (1) year.

[2] Zion's ZNWAB Warrants expired on May 2, 2017, and the ZNWAC Warrants expired on May 2, 2018.

[3] On December 4, 2018, the Company extended the termination date of the Warrants by one (1) year.