Note 18 - Stockholders' Equity (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Stockholders' Equity Attributable to Parent, Ending Balance	$ 2,422,230	$ 2,460,947	$ 2,446,251	$ 2,418,144
Stockholders' Equity, Period Increase (Decrease), Total	(24,000)
Net Income (Loss) Attributable to Parent, Total	75,028	73,384
Share-Based Payment Arrangement, Noncash Expense, Total	1,600
Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan	945	868
Other Comprehensive Income (Loss), Net of Tax, Total	(42,912)	(3,624)
Treasury Stock, Value, Acquired, Cost Method	32,896
Dividends, Common Stock, Cash	25,515	24,650
Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation	$ 285	$ 1,279