Note 13 - Stock Repurchase Programs (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended			77 Months Ended
	Sep. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021	Sep. 30, 2018
Stock Repurchase Program, Authorized Amount	$ 250,000					$ 250,000
Stock Repurchase Program, Period in Force (Month)	24 months
Payments for Repurchase of Common Stock		$ 125,992	$ (0)	$ (0)	$ 431,539
Treasury Stock Acquired, Average Cost Per Share (in dollars per share)					$ 47.81
Treasury Stock [Member]
Shares Acquired Under Stock Repurchases Program, Shares (in shares)		350,000	0	0	9,026,706