Defined Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2021

Compensation And Retirement Disclosure [Abstract]

Obligations and Funded Status

(In millions)	Pension Benefits						Postretirement Benefits
Obligations and Funded Status at December 31	2021			2020			2021			2020
Change in the Projected Benefit Obligation (PBO):
Projected benefit obligation at beginning of year	$	933.5		$	877.1		$	13.4		$	3.6
Projected benefit obligation acquired(a)		—			—			—			9.6
Service cost		0.4			0.4			0.6			0.4
Interest cost		24.0			28.3			0.4			0.2
Actuarial (loss) gain		(32.4	)		70.6			(0.7	)		0.2
Benefits paid		(40.2	)		(42.9	)		(0.4	)		(0.6	)
Projected benefit obligation at end of year	$	885.3		$	933.5		$	13.3		$	13.4
Accumulated benefit obligation at end of year    (excludes the impact of future compensation increases)	$	885.3		$	933.5		$	—		$	—
Change in Plan Assets:
Fair value of plan assets at beginning of year	$	784.9		$	677.2		$	—		$	—
Actual return on plan assets		48.4			101.3			—			—
Employer contributions		22.9			49.3			0.4			0.6
Benefits paid		(40.2	)		(42.9	)		(0.4	)		(0.6	)
Fair value of plan assets at end of year	$	816.0		$	784.9		$	—		$	—
Funded status (Fair value of plan assets less PBO)	$	(69.3	)	$	(148.6	)	$	(13.3	)	$	(13.4	)

(a)Related to the Larson acquisition discussed in Note 4.

Amounts Recognized in Consolidated Balance Sheets

Amounts recognized in the consolidated balance sheets consist of:

	Pension Benefits						Postretirement Benefits
(In millions)	2021			2020			2021			2020
Current benefit payment liability	$	(1.4	)	$	(1.4	)	$	(1.5	)	$	(1.1	)
Accrued benefit liability		(67.9	)		(147.2	)		(11.8	)		(12.3	)
Net amount recognized	$	(69.3	)	$	(148.6	)	$	(13.3	)	$	(13.4	)

Amounts in Accumulated Other Comprehensive Loss that have not yet been Recognized as Components of Net Periodic Benefit Cost

The amounts in accumulated other comprehensive loss on the consolidated balance sheets that have not yet been recognized as components of net periodic benefit cost were as follows:

(In millions)	Pension Benefits			Postretirement Benefits
Net actuarial loss (gain) at December 31, 2019	$	87.7		$	(0.3	)
Recognition of actuarial loss		(2.7	)		(0.1	)
Current year actuarial loss		2.1			1.0
Net actuarial loss due to curtailment		(0.6	)		—
Net actuarial loss (gain) at December 31, 2020	$	86.5		$	0.6
Recognition of actuarial loss		(1.1	)		0.3
Current year actuarial gain		(45.8	)		(0.9	)
Net actuarial loss at December 31, 2021	$	39.6		$	(0.0	)

Components of Net Periodic Benefit Cost for Pension and Postretirement Benefits

Components of net periodic benefit cost were as follows:

Components of Net Periodic Benefit (Income) Cost	Pension Benefits									Postretirement Benefits
(In millions)	2021			2020			2019			2021			2020		2019
Service cost	$	0.4		$	0.4		$	0.4		$	0.6		$	0.4	$	0.2
Interest cost		24.0			28.3			32.9			0.4			0.2		0.2
Expected return on plan assets		(34.9	)		(32.8	)		(35.2	)		—			—		—
Recognition of actuarial losses (gains)		1.1			2.7			34.1			(0.3	)		0.1		0.6
Settlement/Curtailment losses (gains)		—			0.6			0.1			—			—		(0.1	)
Amortization of prior service credits		—			—			—			—			—		0.2
Net periodic benefit (income) cost	$	(9.4	)	$	(0.8	)	$	32.3		$	0.7		$	0.7	$	1.1

Schedule of Assumptions Used

Assumptions	Pension Benefits									Postretirement Benefits
	2021			2020			2019			2021			2020			2019
Weighted-Average Assumptions Used to    Determine Benefit Obligations at    December 31:
Discount rate		2.9	%		2.6	%		3.3	%		3.9	%		5.9	%		6.4	%
Weighted-Average Assumptions Used to    Determine Net Cost for Years Ended    December 31:
Discount rate		2.6	%		3.3	%		4.4	%		5.9	%		6.4	%		4.2	%
Expected long-term rate of return on plan assets		4.4	%		4.5	%		4.9	%		—			—			—

Assumed Health Care Cost Trend Rates Used to Determine Benefit Obligations and Net Cost

	Postretirement Benefits
	2021			2020
Assumed Health Care Cost Trend Rates Used to Determine    Benefit Obligations and Net Cost at December 31:
Health care cost trend rate assumed for next year	6.3/6.7	%	(a)	6.4/7.4	%	(a)
Rate that the cost trend rate is assumed to decline    (the ultimate trend rate)	4.5	%		4.5	%
Year that the rate reaches the ultimate trend rate	2028			2027

(a)The pre-65 initial health care cost trend rate is shown first / followed by the post-65 rate.

Fair Value of Pension Assets by Major Category of Plan Assets

The fair value of the pension assets by major category of plan assets as of December 31, 2021 and 2020 were as follows:

(In millions)	Total as of balance sheet date
	2021		2020
Group annuity/insurance contracts (level 3)	$	25.5	$	24.8
Collective trusts:
Cash and cash equivalents		10.5		16.0
Equity		221.1		287.6
Fixed income		512.1		410.0
Multi-strategy hedge funds		22.0		24.6
Real estate		24.8		21.9
Total	$	816.0	$	784.9

Reconciliation of Level Three Measurements

A reconciliation of Level 3 measurements was as follows:

	Group annuity/ insurance contracts
(In millions)	2021		2020
January 1	$	24.8	$	24.2
Actual return on assets related to assets still held		0.7		0.6
December 31	$	25.5	$	24.8

Schedule of Expected Benefit Payments

The following retirement benefit payments are expected to be paid:

(In millions)	Pension Benefits		Postretirement Benefits
2022	$	42.6	$	1.2
2023		43.4		1.1
2024		44.3		1.1
2025		45.5		1.1
2026		46.4		1.1
Years 2027-2031		237.3		5.9