Note 18 - Income Taxes - Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets (liabilities):
Net foreign deferred taxes, primarily depreciation	$ (61,961)	$ (36,413)
Depreciation, deferred tax liability	(65,315)
Depreciation, deferred tax asset		(10,253)
Intangible drilling costs	13,003	24,856
Net capital loss carryforward - U.S.	55,084	127,633
Tax monetization transaction	(13,134)	(96,293)
State and Investment tax credits	813	1,341
Production tax credits	85,193	82,435
Foreign tax credits	86,206
Withholding tax	(14,400)
Stock options amortization	1,166	1,476
Basis difference in partnership interest	(16,817)	(18,200)
Accrued liabilities and other	3,109	3,241
Total deferred tax assets (liabilities)	72,947	79,823
Less - valuation allowance	(77,571)	(116,234)	$ (92,898)	$ (183,598)
Total	(4,624)
Total	$ (4,719)	$ (36,411)	$ (28,989)