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Note 5 - Long-term Debt - Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Long-term debt	$ 100,000
Debt Premium
Debt Issuance Costs	(7,635)
Total	92,365
Revolving Credit Facility [Member]
Long-term debt
Multicurrency Credit Facility [Member]
Long-term debt
Norwegian Facility [Member]
Long-term debt
Predecessor [Member]
Long-term debt		$ 489,797
Debt Premium		423
Debt Issuance Costs		(6,894)
Total		483,326
Predecessor [Member] \| Revolving Credit Facility [Member]
Long-term debt
Predecessor [Member] \| Multicurrency Credit Facility [Member]
Long-term debt		49,000
Predecessor [Member] \| Norwegian Facility [Member]
Long-term debt		11,157
Term Loan [Member]
Long-term debt	100,000
Term Loan [Member] \| Predecessor [Member]
Long-term debt
Senior Note Due 2022 [Member]
Long-term debt
Senior Note Due 2022 [Member] \| Predecessor [Member]
Long-term debt		429,640
Debt Premium		400
Debt Issuance Costs		$ (6,900)