Pensions and Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2015

Compensation and Retirement Disclosure [Abstract]

Summary of change in defined benefit and postretirement benefit plans

The following tables set forth the change in benefit obligation, plan assets, funded status and amounts recognized in the consolidated balance sheet for the defined benefit pension and postretirement benefit plans as of December 31, 2015 and 2014:

	Pension Benefits						Postretirement Benefits
	2015			2014			2015			2014
	(In millions)
Change in benefit obligation
Benefit obligation at beginning of year	$	61.1		$	52.1		$	17.0		$	16.2
Service cost	2.6			2.2			—			—
Interest cost	2.3			2.2			0.5			0.6
Actuarial (gains) losses	(3.0		)	8.8			(2.7		)	1.9
Plan amendment	—			0.4			—			—
Benefits and expenses paid, net of contributions	(4.6		)	(4.6		)	(1.3		)	(1.7		)
Benefit obligation at end of year	$	58.4		$	61.1		$	13.5		$	17.0
Change in plan assets
Fair value of plan assets at beginning of year	$	125.7		$	125.4		$	—		$	—
Actual return on plan assets	(2.9		)	5.8			—			—
Company contributions	—			—			1.3			1.7
Cash transfer to fund postretirement benefit payments	(0.9		)	(0.9		)	—			—
Benefits and expenses paid, net of contributions	(4.6		)	(4.6		)	(1.3		)	(1.7		)
Fair value of plan assets at end of year	$	117.3		$	125.7		$	—		$	—
Funded (underfunded) status of the plans	$	58.9		$	64.6		$	(13.5	)	$	(17.0	)

Amounts recognized in the consolidated balance sheets consist of:

	Pension Benefits				Postretirement Benefits
	2015		2014		2015			2014
	(In millions)
Noncurrent assets	$	58.9	$	64.6	$	—		$	—
Noncurrent liabilities	—		—		12.1			15.4
Current liabilities	—		—		1.4			1.6
	$	58.9	$	64.6	$	13.5		$	17.0
Amounts recognized in accumulated other comprehensive loss
Net actuarial loss	$	25.2	$	15.3	$	4.4		$	7.6
Net prior service cost (credit)	0.3		0.4		(0.3		)	(0.4		)
Accumulated other comprehensive loss	$	25.5	$	15.7	$	4.1		$	7.2

Summary of Pension Plan Weighted-Average Asset Allocation

The pension plan weighted-average asset allocation at December 31, 2015 and 2014 and target allocation for 2016 are as follows:

		Plan Assets
	Target 2016	2015		2014
Asset Category
Equity securities	45-75%	62.7	%	64.6	%
Debt securities	20-40	25.4	%	27.9	%
Other	0-20	11.9	%	7.5	%
	100%	100	%	100	%

Schedule of Fair Value Hierarchy of Pension Plans Assets

The following table sets forth, by level within the fair value hierarchy, the pension plans assets:

	2015								2014
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	(In millions)
Collective trust and pooled insurance funds:
Common stock	$	38.3	$	1.5	$	—	$	39.8	$	45.6	$	2.2	$	—	$	47.8
Equity Funds	29.1		—		—		29.1		29.0		—		—		29.0
Foreign Stock	5.7		—		—		5.7		5.4		—		—		5.4
U.S. Government obligations	7.4		—		—		7.4		7.0		—		—		7.0
Fixed income funds	14.6		—		—		14.6		19.6		—		—		19.6
Corporate Bonds	6.8		—		—		6.8		7.5		—		—		7.5
Cash and Cash Equivalents	1.2		—		—		1.2		1.8		—		—		1.8
Hedge funds	—		—		12.7		12.7		—		—		7.6		7.6
	$	103.1	$	1.5	$	12.7	$	117.3	$	115.9	$	2.2	$	7.6	$	125.7

Summary of Reconciliation of Level 3 Assets Held

The following table presents a reconciliation of Level 3 assets, as defined in Note 1, held during the years ended December 31, 2015 and 2014.

	Balance at Beginning of Year		Net Unrealized Gain		Purchases		Balance at End of Year
	(In millions)
Hedge Funds:
2015	$	7.6	$	0.1	$	5.0	$	12.7
2014	$	7.3	$	0.3	$	—	$	7.6

Summary of Assumptions Used in the valuation of pension and postretirement benefit obligations

The following tables summarize the assumptions used in the valuation of pension and postretirement benefit obligations at December 31, and to measure the net periodic benefit cost in the following year.

	Weighted-Average assumptions as of December 31,
	Pension Benefits						Postretirement Benefits
	2015		2014		2013		2015		2014		2013
Discount rate	4.13	%	3.82	%	4.51	%	3.80	%	3.60	%	4.21	%
Expected return on plan assets	8.25	%	8.25	%	8.25	%	N/A		N/A		N/A
Rate of compensation increase	3.00	%	3.00	%	2.00	%	N/A		N/A		N/A
Medical health care benefits rate increase	N/A		N/A		N/A		6.75	%	7.00	%	6.50	%
Medical drug benefits rate increase	N/A		N/A		N/A		6.75	%	7.00	%	6.50	%
Ultimate health care cost trend rate	N/A		N/A		N/A		5.00	%	5.00	%	5.00	%
Year of ultimate trend rate	N/A		N/A		N/A		2022		2022		2042

Summary of Components of Net Periodic Benefit Cost

In determining its expected return on plan assets assumption for the year ended December 31, 2015, the Company considered historical experience, its asset allocation, expected future long-term rates of return for each major asset class, and an assumed long-term inflation rate. Based on these factors, the Company derived an expected return on plan assets for the year ended December 31, 2015 of 8.25%. This assumption was supported by the asset return generation model, which projected future asset returns using simulation and asset class correlation.

	Pension Benefits									Postretirement Benefits
	2015			2014			2013			2015			2014			2013
	(In millions)
Components of net periodic benefit cost
Service costs	$	2.6		$	2.2		$	2.6		$	—		$	—		$	0.1
Interest costs	2.3			2.2			2.0			0.6			0.6			0.6
Expected return on plan assets	(10.2		)	(10.1		)	(8.9		)	—			—			—
Amortization of prior service cost (credit)	—			0.1			—			(0.1		)	(0.1		)	(0.1		)
Recognized net actuarial loss	0.3			—			0.8			0.5			0.5			0.7
Benefit (income) costs	$	(5.0	)	$	(5.6	)	$	(3.5	)	$	1.0		$	1.0		$	1.3
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive (income) loss
AOCI at beginning of year	$	15.7		$	2.2		$	20.3		$	7.2		$	5.8		$	7.6
Net loss (gain) arising during the year	10.1			13.1			(17.3		)	(2.7		)	1.8			(1.2		)
Recognition of prior service credit	—			—			—			0.1			0.1			0.1
Recognition of actuarial loss	(0.3		)	0.4			(0.8		)	(0.5		)	(0.5		)	(0.7		)
Total recognized in accumulated other comprehensive loss at end of year	$	25.5		$	15.7		$	2.2		$	4.1		$	7.2		$	5.8

Summary Company's Expected Future Benefit Payments

Below is a table summarizing the Company’s expected future benefit payments and the expected payments due to Medicare subsidy over the next ten years:

			Postretirement Benefits
	Pension Benefits		Gross		Expected Medicare Subsidy		Net including Medicare Subsidy
	(In millions)
2016	$	4.2	$	1.6	$	0.1	$	1.5
2017	4.5		1.5		0.1		1.4
2018	4.3		1.4		0.1		1.3
2019	4.3		1.3		0.1		1.2
2020	4.5		1.2		0.1		1.1
2021 to 2025	22.9		5.2		0.5		4.7

Summary of One-Percentage-Point Change in Assumed Healthcare Cost Trend Rate

A one-percentage-point change in the assumed health care cost trend rate would have the following effects:

	1-Percentage Point Increase		1-Percentage Point Decrease
	(In millions)
Effect on total of service and interest cost components in 2015	$	—	$	—
Effect on postretirement benefit obligation as of December 31, 2015	$	1.0	$	(0.9	)