Benefit Plans (Tables)

3 Months Ended

Mar. 29, 2020

Benefit Plans [Abstract]

Net Periodic Benefit Cost

Components of Net Periodic Benefit Cost

	Pension Benefits
	Three Months Ended
(millions of dollars)	Mar. 29, 2020			Mar. 31, 2019
Service cost	$	2.0		$	1.8
Interest cost		2.9			3.5
Expected return on plan assets		(5.2	)		(4.6	)
Amortization:
Prior service cost		0.1			0.1
Recognized net actuarial loss		2.8			2.3
Net periodic benefit cost	$	2.6		$	3.1

	Other Benefits
	Three Months Ended
(millions of dollars)	Mar. 29, 2020			Mar. 31, 2019
Service cost	$	0.1		$	—
Interest cost		—			0.1
Amortization:
Recognized net actuarial (gain)		(0.2	)		(0.2	)
Net periodic benefit cost	$	(0.1	)	$	(0.1	)