Note 7 - Income Taxes - Net Income Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Total assets	$ 1,053,903	$ 1,361,252	$ 1,716,355
Deferred income tax liabilities	58,094	99,439
Components to Income Tax Assets and Liabilities [Member]
Prepaid expenses and other current assets	1,379	1,386
Total assets	1,379	1,386
Deferred income tax liabilities	58,094	99,439
Total tax liabilities	$ 58,094	$ 99,439