Leases (Schedule of lease costs) (Details) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2020	Aug. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Finance Lease, Right-of-Use Asset, Amortization	$ 1,406	$ 2,757	$ 4,001
Finance Lease, Interest Expense	54	165	382
Operating Lease, Cost	1,331	3,604	4,034
Short-term lease cost	3,664	8,190	38,868
Variable Lease, Cost	64	223	351
Lease, Cost	6,519	14,939	47,636
Capitalized costs included in short-term lease costs	$ 200	$ 1,500	$ 24,700