Stockholders' Equity - Stock Options and Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Warrants, Number of Shares [Roll Forward]
Warrants, Outstanding, Beginning of Period (in shares)	30,000
Warrants, Granted (in shares)	0
Warrants, Exercised (in shares)	0
Warrants, Forfeited (in shares)	0
Warrants, Expired (in shares)	0
Warrants, Outstanding, End of Period (in shares)	30,000	30,000
Warrants Weighted Average Exercise Price [Roll Forward]
Warrants, Granted (in dollars per share)	$ 0.00
Warrants, Exercised (in dollars per share)	0.00
Warrants, Forfeited (in dollars per share)	0.00
Warrants, Expired (in dollars per share)	0.00
Warrants Outstanding, End of Period (in dollars per share)	$ 5.89	$ 5.89
Warrants, Outstanding, Weighted Average Remaining Contractual Term	2 years 11 months 12 days	3 years 2 months 9 days
Warrants Outstanding, Aggregate Intrinsic Value	$ 0	$ 0
Warrants, Vested and expected to vest (in shares)	30,000
Weighted Average Exercise Price, Warrants Vested And Expected To Vest	$ 5.89
Warrants, Vested and expected to vest, Weighted Average Remaining Contractual Term	2 years 11 months 12 days
Warrants, Vested and expected to vest, Aggregate Intrinsic Value	$ 0
Warrants, Vested (in shares)	30,000
Warrants, Vested, Weighted Average Exercise Price (in dollars per share)	$ 5.89
Warrants, Vested, Weighted Average Remaining Contractual Term	2 years 11 months 12 days
Warrants, Vested, Aggregate Intrinsic Value	$ 0
US Equity Plan [Member]
Options, Outstanding [Roll Forward]
Options, Outstanding, Beginning of Period (in shares)	1,044,417
Options, Granted (in shares)	235,776
Options, Exercised (in shares)	0
Options, Forfeited (in shares)	0
Options, Expired (in shares)	0
Options, Outstanding, End of Period (in shares)	1,280,193	1,044,417
Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options, Outstanding. Beginning of Period (in dollars per share)	$ 18.31
Options, Granted (in dollars per share)	3.28
Options, Exercised (in dollars per share)	0.00
Options, Forfeited (in dollars per share)	0.00
Options, Expired (in dollars per share)	0.00
Options, Outstanding, End of Period (in dollars per share)	$ 15.54	$ 18.31
Options, Outstanding, Weighted Average Remaining Contractual Term	6 years 6 months 15 days	6 years 22 days
Options, Outstanding, Aggregate Intrinsic Value	$ 0	$ 0
Options, Vested and expected to vest (in shares)	1,244,418
Options, Vested and expected to vest, Weighted Average Exercise Price (in dollars per share)	$ 15.88
Options, Vested and expected to vest, Weighted Average Remaining Contractual Term	6 years 5 months 16 days
Options, Vested and expected to vest, Aggregate Intrinsic Value	$ 0
Options, Vested (in shares)	946,985
Options, Vested, Weighted Average Exercise Price (in dollars per share)	$ 19.63
Options, Vested, Weighted Average Remaining Contractual Term	5 years 7 months 6 days
Options, Vested, Aggregate Intrinsic Value	$ 0