Note 18 - Stockholders' Equity (Details Textual) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		21 Months Ended
	Feb. 21, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Equity, Attributable to Parent		$ 2,638,736	$ 2,419,559	$ 2,638,736	$ 2,419,559	$ 2,638,736	$ 2,602,671	$ 2,474,040	$ 2,431,532	$ 2,446,251
Stockholders' Equity, Period Increase (Decrease)				164,700
Net Income (Loss) Attributable to Parent		82,371	99,035	271,598	263,041
Share-Based Payment Arrangement, Noncash Expense				4,900
Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan				2,700	2,793
Stock Issued During Period, Value, Issued for Services				850	849
Dividends, Common Stock, Cash		24,672	25,059	73,938	76,111
Other Comprehensive Income (Loss), Net of Tax		(24,484)	(41,546)	(21,238)	(109,809)
Treasury Stock, Value, Acquired, Cost Method	$ 16,600	9	46,290	16,683	109,774	16,700
Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation		$ 11	$ 849	$ 3,538	$ 2,864	$ 3,500