CONVERTIBLE NOTES (Tables)

12 Months Ended

Dec. 31, 2018

Seven Point Five Percentage Convertible Notes [Member]

Fair Value Measurements, Recurring and Nonrecurring

The Company prepared a valuation of the fair value of the 2021 Notes (a Level 3 valuation) for the issuance dates. The value of the 2021 Notes was estimated by implementing the binomial model. The liability component was valued based on the Income Approach. The following parameters were used:

	December 7, 2016			July 24, 2017
Stock price (USD)		0.3			0.77
Expected term		4.94			4.32
Risk free rate		1.86	%		1.74	%
Volatility		54.12	%		63.79	%
Yield		13.98	%		11.56	%

Four Point Five Percentage Convertible Notes One [Member]

Fair Value Measurements, Recurring and Nonrecurring

The Company prepared a valuation of the fair value of the 2022 Notes (a Level 3 valuation) for the issuance date. The value of the 2022 Notes was estimated by implementing the binomial model. The liability component was valued based on the Income Approach. The following parameters were used:

	July 24, 2017
Stock price (USD)		0.77
Expected term		4.57
Risk free rate		1.78	%
Volatility		62.68	%
Yield		15.21	%

Notes 2018 [Member]

Schedule of Interest Expense Recognized

The following table sets forth total interest expense recognized for the years ended December 31, 2016, 2017 and 2018 related to the 2018 Notes:

	Year ended December 31,
(U.S. Dollars in thousands)	2016		2017		2018
Contractual interest expense	$	2,943	$	501	$	139
Amortization of debt issuance costs and debt discount		421		71		15
Gain from early redemption						(32	)
Total	$	3,364	$	572	$	122

Notes 2021 [Member]

Schedule of Interest Expense Recognized

The following table sets forth total interest expense recognized related to the 2021 Notes:

	Year Ended December 31,
(U.S. Dollars in thousands)	2016			2017			2018
Contractual interest expense	$	313		$	4,434		$	4,359
Debt discount amortization		147			2,309			2,587
Gain on extinguishment		(14,063	)
Change in fair value of convertible note embedded derivative		6,473			38,061
Interest payment in connection with conversions					3,918			234
Loss (Income) in connection with conversions					(1,643	)		245
Total	$	(7,130	)	$	47,079		$	7,425

Notes 2022 [Member]

Schedule of Interest Expense Recognized

The following table sets forth total interest expense recognized related to the 2022 Notes:

(U.S. Dollars in thousands)	Year Ended December 31, 2017
Contractual interest expense	$	55
Debt premium amortization		(46	)
Loss on extinguishment		1,325
Total	$	1,334