Note 12 - Operating Segment Information - Operating Income (Loss) by Operating Segment (Details) - USD ($) $ in Thousands		3 Months Ended								6 Months Ended	12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Revenue		$ 26,617	$ 27,821	$ 30,487	$ 38,794	$ 50,585	$ 60,668	$ 74,461	$ 89,092		$ 123,719	$ 274,806	$ 495,769
Direct operating expenses											83,165	169,837	236,244
Drydock expense											4,662	15,387	24,840
General and administrative expense											37,663	47,280	62,728
Depreciation and amortization											58,182	72,591	75,336
Total reduction in value of assets										$ 160,200	162,808	152,103	8,995
Gain on sale of assets and other											8,564	1,160	(14,039)
Operating income (loss)		(16,965)	$ (19,766)	$ (66,338)	$ (128,256)	(11,706)	$ (167,081)	$ (4,207)	$ (558)		(231,325)	(183,552)	101,665
Cash and cash equivalents		8,822				21,939					8,822	21,939	50,785		$ 60,566
Long-lived assets	[1]	995,220				1,266,486					995,220	1,266,486	1,500,418	[2]
Total assets		1,053,903				1,361,252					1,053,903	1,361,252	1,716,355
Capital expenditures											16,188	35,428	158,425
North Sea [Member]
Revenue											76,759	142,168	225,253
Direct operating expenses											45,872	84,474	113,140
Drydock expense											2,549	4,112	9,094
General and administrative expense											6,961	9,469	17,226
Depreciation and amortization											24,157	28,724	32,440
Total reduction in value of assets											1,986	22,919	8,551
Gain on sale of assets and other											5,920	1,244	(3,260)
Operating income (loss)											(10,686)	(8,774)	48,062
Cash and cash equivalents		5,436				12,930					5,436	12,930	19,345
Long-lived assets	[1]	440,670				544,904					440,670	544,904	627,728	[2]
Total assets		465,908				589,934					465,908	589,934	725,078
Capital expenditures											12,550	5,992	109,152
South East Asia [Member]
Revenue											14,069	35,524	64,753
Direct operating expenses											11,308	16,483	22,831
Drydock expense											588	4,356	4,400
General and administrative expense											5,218	4,296	5,387
Depreciation and amortization											8,654	10,419	11,168
Total reduction in value of assets											50,437		444
Gain on sale of assets and other											2,648	(59)	(9,200)
Operating income (loss)											(64,784)	29	29,723
Cash and cash equivalents		3,008				4,911					3,008	4,911	15,126
Long-lived assets	[1]	149,668				216,477					149,668	216,477	226,920	[2]
Total assets		158,671				232,356					158,671	232,356	263,487
Capital expenditures											90	253	459
Americas [Member]
Revenue											32,891	97,114	205,763
Direct operating expenses											25,985	68,880	100,273
Drydock expense											1,525	6,919	11,346
General and administrative expense											6,876	9,906	12,837
Depreciation and amortization											22,008	29,827	28,789
Total reduction in value of assets											110,385	129,184
Gain on sale of assets and other											(4)	(25)	(1,579)
Operating income (loss)											(133,884)	(147,577)	54,097
Cash and cash equivalents		364				1,221					364	1,221	7,959
Long-lived assets	[1]	401,425				499,083					401,425	499,083	638,706	[2]
Total assets		424,398				529,654					424,398	529,654	700,558
Capital expenditures											2,751	26,602	45,403
Other [Member]
Revenue
Direct operating expenses
Drydock expense
General and administrative expense											18,608	23,609	27,278
Depreciation and amortization											3,363	3,621	2,939
Total reduction in value of assets
Gain on sale of assets and other
Operating income (loss)											(21,971)	(27,230)	(30,217)
Cash and cash equivalents		14				2,877					14	2,877	8,355
Long-lived assets	[1]	3,457				6,022					3,457	6,022	7,064	[2]
Total assets		$ 4,926				$ 9,308					4,926	9,308	27,232
Capital expenditures											$ 797	$ 2,581	$ 3,412

[1] Vessels under construction are included in other assets until delivered. Revenue, long-lived assets and capital expenditures presented in the table above are allocated to segments based on the location where the vessel is employed, which in some instances differs from the segment where the vessel is legally owned. In 2016, we had $28.5 million in revenue and $371.6 million in long-lived assets attributed to the United States, our country of domicile. In 2015, we had $73.4 million in revenue and $431.7 million in long-lived assets attributed to the United States. In 2014, we had $152.0 million in revenue and $519.8 million in long-lived assets attributed to the United States.

[2] Goodwill is included in the North Sea segment.