Retirement Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2017

Defined Benefit Plan Disclosure [Line Items]

Schedule of Defined Benefit Plans Disclosures

The following tables set forth the change in plan assets, change in projected benefit obligation, rate assumptions and components of net periodic benefit cost as of December 31 with respect to these plans. The measurement dates of the assets and liabilities of both plans were December 31 of the respective years presented.



	Year Ended December 31, 2017
(in thousands)	Hourly Employees’ Pension Plan			Employees’ Retirement Plan				Total
Change in projected benefit obligation
Benefit obligation at beginning of year		$	—		$	20,787		$	20,787
Service cost		—			4			4
Interest cost		—			831			831
Liability actuarial (gain) loss		—			866			866
Benefits paid		—			(936		)	(936		)
Benefit obligation at end of year		—			21,552			21,552
Change in fair value of plan assets
Fair value of plan assets at beginning of year		—			17,858			17,858
Return on plan assets		—			2,505			2,505
Employer contributions		—			900			900
Benefits paid		—			(936		)	(936		)
Fair value of plan assets at end of year		—			20,327			20,327
Underfunded status - December 31, 2017		$	—		$	(1,225	)	$	(1,225	)



	Year Ended December 31, 2016
(in thousands)	Hourly Employees’ Pension Plan				Employees’ Retirement Plan				Total
Change in projected benefit obligation
Benefit obligation at beginning of year		$	9,649			$	20,561		$	30,210
Service cost		8				4			12
Interest cost		401				886			1,287
Liability actuarial (gain)		(148		)		204			56
Benefits paid		(575		)		(868		)	(1,443		)
Settlements		(9,335		)		—			(9,335		)
Benefit obligation at end of year		—				20,787			20,787
Change in fair value of plan assets
Fair value of plan assets at beginning of year		9,019				16,692			25,711
Return on plan assets		119				1,284			1,403
Employer contributions		772				750			1,522
Benefits paid		(575		)		(868		)	(1,443		)
Settlements		(9,335		)		—			(9,335		)
Fair value of plan assets at end of year		—				17,858			17,858
Underfunded status - December 31, 2016		$	—			$	(2,929	)	$	(2,929	)

Schedule of Assumptions Used

Assumptions used to determine benefit obligations at December 31:



	Hourly Employees’ Pension Plan		Employees’ Retirement Plan
	2017	2016	2017	2016
Discount rate	N/A	N/A	3.60%	4.10%
Composite rate of compensation increase	N/A	N/A	N/A	N/A

Assumptions used to determine net periodic benefit cost for the years ended December 31:



	Hourly Employees’ Pension Plan		Employees’ Retirement Plan
	2017	2016	2017	2016
Discount rate	N/A	4.30%	4.10%	4.40%
Long-term rate of return on plan assets	N/A	7.25%	7.25%	7.25%
Composite rate of compensation increase	N/A	N/A	N/A	N/A

Schedule of Net Benefit Costs

The following tables present the components of net periodic benefit cost (gains are denoted with parentheses and losses are not):



	Year Ended December 31, 2017
(in thousands)	Hourly Employees’ Pension Plan			Employees’ Retirement Plan				Total
Service cost		$	—		$	4		$	4
Interest cost		—			831			831
Expected return on plan assets		—			(1,275		)	(1,275		)
Amortization of net loss		—			433			433
Net periodic benefit cost		$	—		$	(7	)	$	(7	)



	Year Ended December 31, 2016
(in thousands)	Hourly Employees’ Pension Plan				Employees’ Retirement Plan				Total
Service cost		$	8			$	4		$	12
Interest cost		401				886			1,287
Expected return on plan assets		(648		)		(1,196		)	(1,844		)
Amortization of net loss		284				440			724
Recognition of Settlement		2,889				—			2,889
Net periodic benefit cost		$	2,934			$	134		$	3,068

Schedule of Allocation of Plan Assets

The pension plans' weighted-average asset allocations as a percentage of plan assets at December 31 are as follows:



	Hourly Employees’ Pension Plan		Employees’ Retirement Plan
	2017	2016	2017	2016
Equity securities	—%	—%	55%	54%
Debt securities	—%	—%	38%	38%
Short-term investments	—%	—%	2%	3%
Other	—%	—%	5%	5%
Total	—%	—%	100%	100%

Fair Value, Assets Measured on Recurring Basis

The following table presents the hierarchy levels for our postretirement benefit plan investments as of December 31 as described in Note 1 to the Consolidated Financial Statements:



(in thousands)		December 31, 2017			Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
Mutual Funds:
	Mid Cap		$	1,321		$	1,321		$	—		$	—
	Large Cap		2,930			2,930			—			—
	International		2,300			2,300			—			—

Common/Collective Trusts:
	Liability Driven Solution		2,845			—			2,845			—
	Wells Fargo BlackRock International Equity		859			—			859			—
	Wells Fargo Core Bond		1,416			—			1,416			—
	Wells Fargo/Causeway		861			—			861			—
	Wells Fargo BlackRock Large Cap Growth Index Fund		1,146			—			1,146			—
	Wells Fargo BlackRock Large Cap Value Index Fund		1,146			—			1,146			—
	Wells Fargo Multi-Manager Small Cap		1,387			—			1,387			—
	Wells Fargo Russell 2000 Index Fund		636			—			636			—
	Wells Fargo S&P Mid Cap Index Fund		715			—			715			—
	Wells Fargo/MFS Value CIT F		578			—			578			—
	Wells Fargo/T. Rowe Price I Large-Cap Growth Managed CIT		577			—			577			—
	Wells Fargo/T. Rowe Price Equity Income		577			—			577			—
	Wells Fargo Voya Large Cap Growth CIT F		577			—			577			—

Cash & Short-term Investments			456			456			—			—
	Total		$	20,327		$	7,007		$	13,320		$	—



(in thousands)		December 31, 2016			Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
Mutual Funds:
	Mid Cap		$	680		$	680		$	—		$	—
	Large Cap		3,553			3,553			—			—
	International		2,010			2,010			—			—

Common/Collective Trusts:
	Liability Driven Solution		2,522			—			2,522			—
	Wells Fargo BlackRock International Equity		727			—			727			—
	Wells Fargo Core Bond		1,254			—			1,254			—
	Wells Fargo/Causeway		741			—			741			—
	Wells Fargo BlackRock Large Cap Growth Index Fund		1,009			—			1,009			—
	Wells Fargo BlackRock Large Cap Value Index Fund		1,006			—			1,006			—
	Wells Fargo Multi-Manager Small Cap		1,189			—			1,189			—
	Wells Fargo Russell 2000 Index Fund		560			—			560			—
	Wells Fargo S&P Mid Cap Index Fund		630			—			630			—
	Wells Fargo/MFS Value CIT F		501			—			501			—
	Wells Fargo/T. Rowe Price I Large-Cap Growth Managed CIT		505			—			505			—
	T. Rowe Price Equity Income		504			—			504			—

Cash & Short-term Investments			467			467			—			—
	Total		$	17,858		$	6,710		$	11,148		$	—

Schedule of Expected Benefit Payments

The following table illustrates the estimated pension benefit payments that are projected to be paid:



(in thousands)	Employees’ Retirement Plan
2018		$	1,125
2019		1,146
2020		1,160
2021		1,220
2022		1,253
Years 2023 through 2027		6,348

Supplemental Employee Retirement Plans, Defined Benefit