Note 3 - Impairment Charges - Components of Reduction in Value of Assets (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2016	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill impairment				$ 22,554
Intangible asset impairment				13,695
Assets held for sale	$ 2,600				1,536
Total reduction in value of assets		$ 160,200	162,808	152,103	8,995
Long-Lived Assets [Member]
Assets impairment			160,222	115,489
Vessel Component [Member]
Assets impairment			$ 2,586	$ 365	$ 7,459