Note 23 - Incentive Plans (Details Textual) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2022	May 31, 2020
Share-Based Payment Arrangement, Expense		$ 26.6	$ 23.2	$ 23.7
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 43.1
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		2 years 9 months 18 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)		0	0	0
Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit (in dollars per share)		$ 20.41
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit (in dollars per share)		$ 24.12
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year)		2 months 12 days
Proceeds from Stock Options Exercised		$ 4.2	$ 6.1	$ 1.0
Common Stock, Shares, Issued (in shares)		618,483,565	616,658,593
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent		5.00%
Defined Contribution Plan, Cost		$ 2.6	$ 2.4	2.3
Employee [Member]
Severance Costs		$ 1.5	14.4	$ 8.7
Employee [Member] | Merger Charges [Member]
Severance Costs			$ 13.7
Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)		$ 24.27	$ 17.81	$ 18.67
Dividend, Share-Based Payment Arrangement, Shares		$ 2.5	$ 1.8	$ 2.2
Performance Shares [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)		$ 31.19	$ 22.96	$ 18.02
Common Stock, Shares, Issued (in shares)		998,238	814,160	594,900
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	[1]	0.00%	0.00%	0.00%
The 2020 Equity Participation Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)						10,000,000.0
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)					6,900,000

[1] Total Shareholder Returns, as used in the performance share awards computation, are measured based on cumulative dividend stock prices, as such a zero percent dividend yield is utilized.