Note 10 - Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal									$ (2,196)	$ 20,943	$ 26,820
State									36,787	39,466	36,639
Total Current									34,591	60,409	63,459
Deferred:
Federal									(3,234)	7,464	1,495
State									(6,252)	2,361	848
Total Deferred									(9,486)	9,825	2,343
Total income tax expense	$ 10,332	$ 2,190	$ 3,492	$ 9,091	$ 16,290	$ 20,973	$ 14,383	$ 18,588	$ 25,105	$ 70,234	$ 65,802