Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2022

Retirement Benefits [Abstract]

Schedule of Components of Retirement Benefit Expense (Benefit)

The following table presents the components of retirement benefits expense (income): 

	Pension Benefits				Postretirement Medical and Life Insurance Benefits
	Three months ended March 31,
	2022		2021		2022		2021
	(In millions)
Interest cost on benefit obligation	$	8.9	$	8.4	$	0.1	$	0.1
Expected return on assets	(15.7)		(15.3)		—		—
Amortization of net losses (gains)	7.7		15.9		(0.7)		(0.6)
Retirement benefits expense (income)	$	0.9	$	9.0	$	(0.6)	$	(0.5)