Retirement Benefit Plans (Tables)

3 Months Ended

Mar. 31, 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
	March 31,
	2019			2018
Service cost	$	6.7		$	7.5
Interest cost		6.2			5.5
Expected return on plan assets		(11.5	)		(11.8	)
Amortization of prior service cost		(1.8	)		(2.5	)
Amortization of unrecognized actuarial loss		5.3			6.1
Net periodic pension expense	$	4.9		$	4.8