Share-Based Compensation Plan - Stock Option Awards (Details) - Stock options - USD ($) $ / shares in Units, shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted Average Exercise Price
Total unrecognized compensation cost	$ 3,000,000
Weighted-average period over which cost is expected to be recognized	1 year 9 months 18 days
Incentive Plan 2017
Shares
Outstanding in beginning of the year (in shares)	1,003
Granted (in shares)	980
Exercised (in shares)	0
Forfeited (in shares)	(57)
Expired (in shares)	(95)
Outstanding at the end of the year (in shares)	1,831	1,003
Exercisable at the end of the period (in shares)	554
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 16.10
Granted (in dollars per share)	5.75
Exercised (in dollars per share)	0
Forfeited (in dollars per share)	15.46
Expired (in dollars per share)	11.30
Outstanding at the end of the period (in dollars per share)	10.83	$ 16.10
Exercisable at the end of the period (in dollars per share)	$ 13.91
Outstanding, Weighted Average Remaining Contractual Term (in years)	8 years 6 months
Exercisable, Weighted Average Remaining Contractual Term (in years)	7 years 9 months 18 days
Outstanding, Aggregate Intrinsic Value	$ 0
Exercisable, Aggregate Intrinsic Value	0
Intrinsic value of options exercised	$ 0	$ 0	$ 0
Weighted-average grant-date fair value of stock options granted (in dollars per share)	$ 2.52	$ 9.12	$ 7.68