Income taxes (Component of Income Tax (Benefit) Expense from Continuing Operations) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 21, 2017	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Current income taxes
Federal	$ 0	$ (162)	$ 0	$ (77)
State	37	(187)	0	0
Total current income taxes	37	(349)	0	(77)
Deferred income taxes
Federal	0	0	0	0
State	0	0	0	0
Total deferred income taxes	0	0	0	0
Income tax (benefit) expense	$ 37	$ (349)	$ 0	$ (77)