Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2018

Compensation And Retirement Disclosure [Abstract]

Components of Estimated Net Pension and Other Postretirement Benefit Plan Income

The components of the estimated net pension and other postretirement benefits plan income for the three months ended March 31, 2018 and 2017 were as follows:

	Three Months Ended
	March 31,
	2018			2017
Pension expense (income):
Service cost	$	0.2		$	0.2
Interest cost		7.8			7.8
Expected return on plan assets		(12.6	)		(12.3	)
Amortization, net		2.0			1.7
Settlements		0.3			—
Net pension income	$	(2.3	)	$	(2.6	)
Other postretirement benefits plan expense (income):
Service cost	$	0.4		$	0.3
Interest cost		2.6			2.8
Expected return on plan assets		(3.5	)		(3.4	)
Amortization, net		(0.7	)		(0.7	)
Net other postretirement benefit income	$	(1.2	)	$	(1.0	)