Note 18 - Pension and Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan [Table Text Block]

	Pension Plan and SERP						Postretirement Plan
	2023			2022			2023			2022
Change in benefit obligation:
Benefit obligation at January 1	$	330.9		$	431.7		$	4.2		$	6.0
Interest cost		17.1			14.7			0.2			0.1
Actuarial (gain) loss		(0.8	)		(86.6	)		1.1			(0.4	)
Plan participants’ contributions		—			—			1.3			1.3
Benefits paid		(29.4	)		(28.9	)		(2.7	)		(2.8	)
Benefit obligation at December 31	$	317.8		$	330.9		$	4.1		$	4.2
Accumulated benefit obligation at December 31	$	317.8		$	330.9
Change in plan assets:
Fair value of plan assets at January 1	$	406.3		$	546.2		$	7.6		$	9.5
Actuarial gain (loss)		47.3			(111.8	)		0.4			(1.1	)
Employer contributions, net		1.7			0.8			1.5			0.7
Plan participants’ contributions		—			—			1.3			1.3
Benefits paid		(29.4	)		(28.9	)		(2.7	)		(2.8	)
Fair value of plan assets at December 31	$	425.9		$	406.3		$	8.1		$	7.6
Funded status at December 31	$	(108.1	)	$	(75.4	)	$	(4.0	)	$	(3.4	)
Amounts recognized in the consolidated balance sheets consist of:
Pension assets, noncurrent (1)	$	(117.4	)	$	(85.6	)	$	(4.0	)	$	(3.4	)
Pension, SERP and postretirement benefits, current (2)		1.0			0.8			—			—
Pension, SERP and postretirement benefits, noncurrent (3)		8.3			9.4			—			—
Total Pension, SERP and Postretirement benefits	$	(108.1	)	$	(75.4	)	$	(4.0	)	$	(3.4	)

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

	Pension Plan and SERP				Postretirement Plan
	2023		2022		2023		2022
Prior service benefit cost	$	2.4	$	2.6	$	—	$	—
Actuarial losses		118.3		147.8		3.6		3.2
Accumulated other comprehensive losses, pretax	$	120.7	$	150.4	$	3.6	$	3.2

			Quoted Prices		Significant
			in Active		Other
			Markets for		Observable
			Identical Assets		Inputs
	Total		(Level 1)		(Level 2)
December 31, 2023
Equity
Managed equity accounts (1)	$	131.6	$	131.6	$	—
Equity — pooled separate account (2)		38.6		—		38.6
Debt
Fixed income manager — separately managed account (5)		138.9		—		138.9
Fixed income manager — pooled separate account (2)		89.2		—		89.2
Fixed income manager — government securities (3)		8.1		8.1		—
Others
Cash — pooled separate account (2)		5.2		—		5.2
Global real estate account (4)		22.4		—		22.4
Total	$	434.0	$	139.7	$	294.3
December 31, 2022
Equity
Managed equity accounts (1)	$	128.8	$	128.8	$	—
Equity — pooled separate account (2)		39.7		—		39.7
Debt
Fixed income manager — separately managed account (5)		133.6		—		133.6
Fixed income manager — pooled separate account (2)		81.5		—		81.5
Fixed income manager — government securities (3)		7.7		7.7		—
Others
Cash — pooled separate account (2)		2.7		—		2.7
Global real estate account (4)		20.2		—		20.2
Total	$	414.2	$	136.5	$	277.7

Schedule of Net Benefit Costs [Table Text Block]

	Pension Plan and SERP									Postretirement Plan
	2023			2022			2021			2023			2022			2021
Interest cost	$	17.1		$	14.7		$	11.0		$	0.2		$	0.1		$	0.1
Expected return on plan assets		(24.1	)		(28.2	)		(32.8	)		(0.1	)		(0.2	)		(0.2	)
Amortization of prior service cost (credit) reclassified from accumulated other comprehensive income		0.2			0.2			0.2			—			—			(0.1	)
Amortization of net actuarial loss reclassified from accumulated other comprehensive income		5.2			4.0			3.8			0.4			0.2			0.2
Net periodic (credit) benefit cost		(1.6	)		(9.3	)		(17.8	)		0.5			0.1			—
Less: Amortization of prior service (cost) credit reclassified from accumulated other comprehensive income		(0.2	)		(0.2	)		(0.2	)		—			—			0.1
Less: Amortization of actuarial loss reclassified from accumulated other comprehensive losses		(0.1	)		(0.2	)		(0.2	)		—			—			—
Less: Net loss recognized reclassified from accumulated other comprehensive losses		(5.1	)		(3.8	)		(3.6	)		(0.4	)		(0.2	)		(0.2	)
Actuarial (gain) loss		(24.3	)		53.5			(31.1	)		0.8			1.0			(0.5	)
Total recognized in other comprehensive income		(29.7	)		49.3			(35.1	)		0.4			0.8			(0.6	)
Total recognized in net periodic benefit credit and other comprehensive (income) loss	$	(31.3	)	$	40.0		$	(52.9	)	$	0.9		$	0.9		$	(0.6	)

Defined Benefit Plan, Assumptions [Table Text Block]

	Pension Plan and SERP						Postretirement Plan
Weighted-average assumptions used to determine benefit obligations:	2023		2022				2023		2022
Discount rate	5.37	%	5.49	%			4.75	%	5.25	%
Expected return on plan assets	6.50	%	6.25	%			1.75	%	1.75	%
Cash balance interest credit rate	4.43	%	2.57	%			N/A
Weighted-average assumptions used to determine net periodic benefit (credit) cost:	2023		2022		2021		2023		2022		2021
Discount rate	5.48	%	2.75	%	2.49	%	5.25	%	2.25	%	1.50	%
Expected return on plan assets	6.25	%	6.25	%	6.50	%	1.75	%	1.75	%	2.00	%
Cash balance interest credit rate	4.43	%	2.57	%	2.57	%	N/A

Schedule of Expected Benefit Payments [Table Text Block]

	Pension Plan		Postretirement
	and SERP		Plan
	Gross		Gross		Medicare			Net
	Benefit		Benefit		Subsidy			Benefit
	Amount		Amount		Payments			Amount
2024	$	29.4	$	0.8	$	(0.1	)	$	0.7
2025	$	28.9	$	0.7	$	—		$	0.7
2026	$	28.4	$	0.6	$	—		$	0.6
2027	$	28.4	$	0.5	$	—		$	0.5
2028	$	27.0	$	0.4	$	—		$	0.4
2029 and thereafter	$	123.3	$	1.4	$	—		$	1.4

Schedule of Allocation of Plan Assets [Table Text Block]

	Target			Percentage of Plan Assets
Asset Category	Allocation			2023			2022
Equity securities		40.0	%		40.0	%		41.4	%
Debt securities		60.0			53.5			52.9
Real Estate		—			5.3			5.0
Other		—			1.2			0.7
Total		100.0	%		100.0	%		100.0	%