Derivative Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of range of assumptions used to determine the fair value of the warrants

The range of assumptions used to determine the fair value of the warrants at each period end was:

	Year Ended December 31, 2017		Year Ended December 31, 2016			Year Ended December 31, 2015
Fair value of Synergy common stock	$	2.23	$	6.09		$	5.67
Expected warrant term	0.2 - 1.9 years		1.2 years			2.2 years
Risk-free interest rate	1.34% - 1.78%		1.03		%	1.18		%
Expected volatility	50%-67%		50		%	50%-80%
Dividend yield	—		—			—

Schedule of changes in derivative financial instruments and associated liability balance

The following table sets forth the components of changes in the Synergy’s outstanding warrants which were deemed derivative financial instruments and the associated liability balance for the periods indicated:

Date	Description	Warrants	Derivative Instrument Liability (in thousands)
12/31/2015	Balance of derivative financial instruments liability	210,000	$	322
12/31/2016	Change in fair value of warrants during the year ended December 31, 2016	—	(106		)
12/31/2016	Balance of derivative financial instruments liability	210,000	216
12/31/2017	Fair value of new warrants issued during the year	21,705,426	21,706
12/31/2017	Change in fair value of warrants during the year ended December 31, 2017	—	(4,340		)
12/31/2017	Balance of derivative financial instruments liability	21,915,426	$	17,582