Rendering

Component: (Network and Table)
Network
2314301 - Disclosure - Pension and other postretirement benefits (Tables)
(http://www.centuryca.com/role/PensionAndOtherPostretirementBenefitsTables)
Table(Implied)
Slicers (applies to each fact value in each table cell)
Compensation and Retirement Disclosure [Abstract]Period [Axis]
2016-01-01 - 2016-12-31
Compensation and Retirement Disclosure [Abstract]
 
Schedule of Changes in Projected Benefit Obligations
The change in benefit obligations and change in plan assets as of December 31 are as follows:

 
Pension
 
OPEB
 
2016
2015
 
2016
2015
Change in benefit obligation:
 
 
 
 
 
Benefit obligation at beginning of year
$
326,571

$
336,292

 
$
132,550

$
158,781

Service cost
4,651

6,346

 
1,003

1,970

Interest cost
13,892

13,388

 
5,595

5,985

Plan amendments


 

(1,758
)
Actuarial loss (gain)
12,761

(11,429
)
 
1,919

(18,150
)
Medicare Part D


 
38


Benefits paid
(29,828
)
(19,247
)
 
(7,249
)
(5,878
)
Curtailment

1,221

 

(8,400
)
  Benefit obligation at end of year
$
328,047

$
326,571

 
$
133,856

$
132,550

 
 
Schedule of Changes in Fair Value of Plan Assets
 
Pension
 
OPEB
 
2016
2015
 
2016
2015
Change in plan assets:
 
 
 
 
 
Fair value of plan assets at beginning of year
$
280,862

$
305,520

 
$

$

Actual return on plan assets
23,932

(11,321
)
 


Employer contributions
1,775

5,910

 
7,211

5,878

Medicare Part D subsidy received


 
38


Benefits paid
(29,828
)
(19,247
)
 
(7,249
)
(5,878
)
Fair value of assets at end of year
$
276,741

$
280,862

 
$

$

 
 
Schedule of Amounts Recognized in Balance Sheet
 
Pension
 
OPEB
 
2016
2015
 
2016
2015
Funded status of plans:
 
 
 
 
 
Funded status
$
(51,306
)
$
(45,709
)
 
$
(133,856
)
$
(132,550
)
Amounts recognized in the Consolidated Balance Sheets:
 

 

 
 

 

Current liabilities
(1,813
)
(1,743
)
 
(7,501
)
(6,551
)
Non-current liabilities
(49,493
)
(43,966
)
 
(126,355
)
(125,999
)
Net amount recognized
$
(51,306
)
$
(45,709
)
 
$
(133,856
)
$
(132,550
)
 
 
 
 
 
 
Amounts recognized in accumulated other comprehensive loss (pre-tax):
 

 
 
 

 
Net loss
$
83,451

$
80,514

 
$
47,957

$
49,562

Prior service cost (benefit)
1,104

1,211

 
(6,595
)
(9,377
)
Total
$
84,555

$
81,725

 
$
41,362

$
40,185

 
 
Schedule of Net Benefit Cost
Net Periodic Benefit Cost:
 
Year Ended December 31,
 
Pension
 
OPEB
 
2016
2015
2014
 
2016
2015
2014
Service cost
$
4,651

$
6,346

$
5,605

 
$
1,003

$
1,970

$
1,591

Interest cost
13,892

13,388

11,629

 
5,595

5,985

6,420

Expected return on plan assets
(18,774
)
(21,241
)
(14,694
)
 



Amortization of prior service costs
106

110

77

 
(2,781
)
(3,728
)
(3,844
)
Amortization of net loss
4,666

3,980

1,907

 
3,537

3,814

3,704

Settlements


4,701

 



Curtailment cost (benefit)

1,235

263

 

(4,266
)

Net periodic benefit cost
$
4,541

$
3,818

$
9,488

 
$
7,354

$
3,775

$
7,871

 
 
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)
Other changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Loss (pre-tax):
 
Year Ended December 31,
 
Pension
 
OPEB
 
2016
2015
 
2016
2015
Net loss (gain)
$
7,603

$
21,133

 
$
1,919

$
(26,686
)
Prior service cost (benefit)


 

(1,758
)
Amortization of net loss, including recognition due to settlement
(4,666
)
(3,980
)
 
(3,537
)
(3,814
)
Amortization of prior service benefit (cost), including recognition due to curtailment
(106
)
(124
)
 
2,781

8,475

Total amount recognized in other comprehensive loss
2,831

17,029

 
1,163

(23,783
)
Net periodic benefit cost
4,541

3,818

 
7,354

3,775

Total recognized in net periodic benefit cost and other comprehensive loss
$
7,372

$
20,847

 
$
8,517

$
(20,008
)
 
 
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year
Amounts in accumulated other comprehensive loss expected to be recognized as components of net periodic benefit cost during 2017
 
Pension
 
OPEB
Amortization of net loss
$
4,926

 
$
3,645

Amortization of prior service cost (benefit)
106

 
(2,781
)
 
 
Weighted Average Assumptions Used in Calculating Benefit Obligation and Net Periodic Benefit Cost
Weighted average assumptions used to determine net periodic benefit cost for the years ended December 31:
 
Pension
 
OPEB
 
2016
2015
2014
 
2016
2015
2014
Measurement date
12/31/2015
12/31/2014
12/31/2013
 
12/31/2015
12/31/2014
12/31/2013
Fiscal year end
12/31/2016
12/31/2015
12/31/2014
 
12/31/2016
12/31/2015
12/31/2014
Discount rate (1)
4.44%
4.05%
4.89%
 
4.50%
4.00%
4.99%
Rate of compensation increase (2)
3%/4%
3%/4%
3%/4%
 
3%/4%
3%/4%
3%/4%
Expected return on plan assets (3)
7.10%
7.16%
7.25%
 

(1)
We use the Ryan Above Median Discount Rate Curve ("Ryan Curve") to determine the discount rate.
(2)
For 2016, the rate of compensation increase is 3% per year for the first two years and 4% per year for year three and thereafter. For 2015, the rate of compensation increase is 3% per year for the first three years and 4% per year for year four and thereafter. For 2014, the rate of compensation increase is 3% per year for the first four years and 4% per year for year five and thereafter.
(3)
The rate for each of our defined benefit plans was selected by taking into account our expected asset mix and is based on historical performance as well as expected future rates of return on plan assets.
 
Weighted average assumptions used to determine benefit obligations at December 31:
 
Pension
 
OPEB
 
2016
2015
 
2016
2015
Discount rate (1)
4.19%
4.44%
 
4.20%
4.50%
Rate of compensation increase (2)
3%/4%
3%/4%
 
3%/4%
3%/4%
Measurement date
12/31/2016
12/31/2015
 
12/31/2016
12/31/2015

 
 
Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates
A one-percentage-point change in the assumed health care cost trend rate would have had the following effects in 2016:
 
1% Increase
 
1% Decrease
Effect on total of service and interest cost
$
933

 
$
(769
)
Effect on accumulated postretirement benefit obligation
16,968

 
(14,290
)
 
 
Schedule of Allocation of Plan Assets
Fair Value of Pension Plans’ assets included under the fair value hierarchy:
As of December 31, 2016
Level 1
Level 2
Level 3
Total
Equities:
 
 
 
 
U.S. equities
$
93,773

$

$

$
93,773

International equities
61,453



61,453

Fixed income
121,515



121,515

Total
$
276,741

$

$

$
276,741

As of December 31, 2015
 

 

 

 

Equities:
 

 

 

 

U.S. equities
$
86,723

$

$

$
86,723

International equities
54,769



54,769

Fixed income
139,370



139,370

Total
$
280,862

$

$

$
280,862

The Pension Plans’ weighted average long-term strategic asset allocation policy targets are as follows:
 
Pension Plan Asset Allocation
 
2016 Target
December 31, 2016
December 31, 2015
Equities:
 
 
 
U.S. equities
33%
34%
30%
International equities
22%
22%
20%
Fixed income
45%
44%
50%
 
 
100%
100%
 
 
Schedule Of Expected Benefit Plan Contributions
We expect to make the following contributions for 2017:
 
2017
Expected pension plan contributions
$
1,813

Expected OPEB benefits payments
7,501

 
 
Schedule of Expected Benefit Payments
The following table provides the estimated future benefit payments for the pension and other postretirement benefit plans:
 
Pension Benefits
 
OPEB Benefits
2017
$
19,705

 
$
7,501

2018
19,562

 
7,519

2019
20,429

 
7,855

2020
20,929

 
8,055

2021
20,819

 
8,287

2022 – 2026
102,567

 
35,560

 
 
Schedule of Multiemployer Plans
Century’s participation in the plan for the year ended December 31, 2016, is outlined in the table below.
Fund
Steelworkers Pension Trust
EIN / PN
23-6648508/499
Pension Protection Act Zone Status 2016 (1)
Green
Pension Protection Act Zone Status 2015 (1)
Green
Subject to Financial Improvement/Rehabilitation Plan
No
Contributions of Century Aluminum 2016
$788
Contributions of Century Aluminum 2015
$1,618
Contributions of Century Aluminum 2014
$2,164
Withdrawal from Plan Probable
No
Surcharge Imposed
No
Expiration Date of Collective Bargaining Agreement
April 1, 2020

(1)
The most recent Pension Protection Act zone status available in 2016 and 2015 is for the plan's year-end December 31, 2015 and December 31, 2014, respectively.  The zone status is based on information that Century received from the plan as well as publicly available information per the Department of Labor and is certified by the plan’s actuary. Among other factors, plans in the green zone are at least 80 percent funded.