Note 4 - Financing Arrangements - Outstanding Borrowings (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Long-term debt	$ 1,243,814	$ 945,257
Less current portion of long-term debt	0	(355,972)
Total long-term debt	1,243,800	945,200
Senior Notes [Member]
Long-term debt	946,800	1,301,200
Revolving Credit Facility [Member]
Long-term debt	$ 297,000	$ 0