Retirement Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2019

Compensation And Retirement Disclosure [Abstract]

Components of Net Periodic Pension Expense

The components of net periodic pension expense for our U.S. and foreign defined benefit pension plans are as follows (in millions):

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2019			2018			2019			2018
Service cost	$	6.4		$	7.0		$	13.1		$	14.5
Interest cost		6.2			5.6			12.4			11.1
Expected return on plan assets		(11.4	)		(11.7	)		(22.9	)		(23.5	)
Amortization of prior service cost		(1.9	)		(2.5	)		(3.7	)		(5.0	)
Amortization of unrecognized actuarial loss		5.5			6.7			10.8			12.8
Net periodic pension expense	$	4.8		$	5.1		$	9.7		$	9.9