Note 10 - Employee Benefit Plans - Weighted-Average Assumptions (Details) - Norwegian Pension Plan [Member]	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2017	Nov. 14, 2017	Dec. 31, 2016
Discount rate	2.40%
Return on plan assets	4.10%
Rate of compensation increase	2.50%
Predecessor [Member]
Discount rate		2.40%	2.60%
Return on plan assets		4.10%	3.60%
Rate of compensation increase		2.50%	2.50%