Note 22 - Incentive Plans (Details Textual) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	May 31, 2020
Share-based Payment Arrangement, Expense		$ 23.2	$ 23.7	$ 20.2
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 36.5
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		2 years 8 months 12 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)		$ 18.44
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)		1 year
Proceeds from Stock Options Exercised		$ 6.1	$ 1.0	$ 3.9
Common Stock, Shares, Issued, Total (in shares)		616,658,593	432,518,743
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent		5.00%
Defined Contribution Plan, Cost		$ 2.4	$ 2.3	2.2
Employee [Member]
Severance Costs		14.4	$ 8.7	$ 2.6
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)		$ 17.81	$ 18.67	$ 18.03
Dividend, Share-based Payment Arrangement, Shares		$ 1.8	$ 2.2	$ 3.0
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)		$ 22.96	$ 18.02	$ 22.00
Common Stock, Shares, Issued, Total (in shares)		814,160	594,900	104,551
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)		8,500,000

[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.