Note 5 - Income Taxes - Provision for Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income tax (provision) benefit	$ 27,000,000	$ (6,000,000)	$ 835,000,000	$ (202,000,000)
Effective tax rate	(10.50%)	2.80%	(64.80%)	15.30%