Pension and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2016

Compensation and Retirement Disclosure [Abstract]

Summary of Net Periodic Pension and Other Postemployment Benefit Costs

Net periodic pension cost recognized during the periods included the following components (in millions):

	Three months ended September 30,						Nine months ended September 30,
	2016			2015			2016			2015
Service cost	$	4.6		$	4.3		$	12.2		$	12.7
Interest cost	6.7			8.0			19.7			23.8
Expected return on plan assets	(9.9		)	(10.6		)	(29.7		)	(31.5		)
Amortization of net loss	5.6			6.4			15.8			19.1
Amortization of prior service credit	(1.2		)	(1.1		)	(3.7		)	(3.4		)
Total net pension cost	$	5.8		$	7.0		$	14.3		$	20.7

Other postretirement benefit cost recognized during the periods included the following components (in millions):

	Three months ended September 30,					Nine months ended September 30,
	2016			2015		2016			2015
Service cost	$	—		$	0.3	$	0.2		$	1.0
Interest cost	0.4			0.7		1.4			2.1
Amortization of net loss	0.2			—		0.2			—
Amortization of prior service credit	(2.9		)	—		(3.1		)	—
Total other postretirement benefit cost	$	(2.3	)	$	1.0	$	(1.3	)	$	3.1

On August 10, 2016, the Company communicated changes to the participants of its postretirement benefits plan that was previously frozen to new entrants in 2008. Based on these changes, effective as of January 1, 2017, eligible participants will now receive a health reimbursement account that provides a fixed dollar benefit per year. The impact of these changes to the plan and related, as of August 10, 2016, are presented in the table below (in millions):

	Liability increase (decrease)			Accumulated other comprehensive income (loss)			Deferred tax liability increase (decrease)
Plan change benefit	$	(39.9	)	$	25.9		$	14.0
Remeasurement loss	5.2			(3.4		)	(1.8		)
Actuarial loss	5.2			(3.3		)	(1.9		)
Total	$	(29.5	)	$	19.2		$	10.3