Equity Compensation Plans - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Number of Options
Outstanding, beginning balance (in Shares)	3,418,000
Granted (in Shares)	2,895,000	0
Exercised (in Shares)	0
Forfeited (in Shares)	(777,000)
Outstanding, ending balance (in Shares)	5,536,000	3,418,000
Options, exercisable (in Shares)	2,087,000
Weighted Average Exercise Price
Outstanding, beginning balance (in Dollars per share)	$ 28.55
Granted (in Dollars per share)	4.30
Exercised (in Dollars per share)	0
Forfeited (in Dollars per share)	26.03
Outstanding, ending balance (in Dollars per share)	16.22	$ 28.55
Weighted average exercise price, exercisable (in Dollars per share)	$ 29.81
Weighted Average Remaining Contractual Term (Years)
Weighted Average Remaining Contractual Term	6 years 6 months 18 days	3 years 8 months 8 days
Weighted Average Remaining Contractual Term, exercisable	2 years 9 months 14 days
Aggregate Intrinsic Value (in thousands)
Aggregate Intrinsic Value	$ 2,474	$ 0
Aggregate Intrinsic Value, exercisable	$ 0