Note 7 - Income Taxes - Current and Deferred Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 87,977	$ 22,904	$ 134,284
State and local	20,981	26,738	23,456
Current income taxes, total	108,958	49,642	157,740
Deferred:
Federal	51,229	97,670	(261,592)
State and local	4,388	3,921	12,828
Deferred income taxes, total	55,617	101,591	(248,764)
Total tax expense/(benefit)	$ 164,575	$ 151,233	$ (91,024)