Accrued Liabilities - Components of Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accrued Liabilities
Accrued product related costs	$ 4,234	$ 4,464
Accrued income taxes	8,573	7,903
Accrued property and other taxes	809	1,574
Accrued professional fees	979	1,599
Contract with Customer, Liability	2,520	2,877
Dividends payable	1,298	1,299
Remediation reserves	8,975	11,444	$ 11,274
Derivative Liability	3,256	0
Other accrued liabilities	3,832	5,218
Total accrued expenses and other liabilities	$ 34,476	$ 36,378