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PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Tables) | 12 Months Ended
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Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items] |
Retirement And Defined Compensation Plans Disclosures [Table Text Block] | The following table summarizes the annual expense (income) recognized related to the retirement plans for 2017, 2016 and 2015:
| (In Millions)
| 2017 |  | 2016 |  | 2015
Defined benefit pension plans | $ | 18.0 |  |  | $ | 16.5 |  |  | $ | 23.9 |
Defined contribution pension plans | 2.9 |  |  | 2.8 |  |  | 3.6 |
Other postretirement benefits | (6.1 | ) |  | (4.0 | ) |  | 4.4 |
Total | $ | 14.8 |  |  | $ | 15.3 |  |  | $ | 31.9 |
Obligations and Funded Status | The following tables and information provide additional disclosures for the years ending December 31, 2017 and 2016:
| (In Millions)
| Pension Benefits |  | Other Benefits
Change in benefit obligations: | 2017 |  | 2016 |  | 2017 |  | 2016
Benefit obligations — beginning of year | $ | 931.6 |  |  | $ | 910.8 |  |  | $ | 264.6 |  |  | $ | 266.0 |
Service cost (excluding expenses) | 17.1 |  |  | 17.6 |  |  | 1.8 |  |  | 1.7 |
Interest cost | 30.5 |  |  | 30.3 |  |  | 8.3 |  |  | 9.1 |
Plan amendments | — |  |  | 5.7 |  |  | — |  |  | 9.8 |
Actuarial (gain) loss | 54.6 |  |  | 38.1 |  |  | 7.4 |  |  | (7.2 | )
Benefits paid | (60.7 | ) |  | (70.9 | ) |  | (21.4 | ) |  | (21.3 | )
Participant contributions | — |  |  | — |  |  | 4.6 |  |  | 6.0 |
Federal subsidy on benefits paid | — |  |  | — |  |  | 0.6 |  |  | 0.5 |
Benefit obligations — end of year | $ | 973.1 |  |  | $ | 931.6 |  |  | $ | 265.9 |  |  | $ | 264.6 |
Change in plan assets: |  |  |  |  |  |  |
Fair value of plan assets — beginning of year | $ | 685.8 |  |  | $ | 700.6 |  |  | $ | 253.0 |  |  | $ | 250.6 |
Actual return on plan assets | 100.2 |  |  | 54.8 |  |  | 24.2 |  |  | 16.0 |
Participant contributions | — |  |  | — |  |  | 0.3 |  |  | 0.5 |
Employer contributions | 24.4 |  |  | 1.2 |  |  | 1.7 |  |  | 1.7 |
Asset transfers | 0.1 |  |  | 0.1 |  |  | — |  |  | — |
Benefits paid | (60.7 | ) |  | (70.9 | ) |  | (16.7 | ) |  | (15.8 | )
Fair value of plan assets — end of year | $ | 749.8 |  |  | $ | 685.8 |  |  | $ | 262.5 |  |  | $ | 253.0 |
Funded status at December 31: |  |  |  |  |  |  |
Fair value of plan assets | $ | 749.8 |  |  | $ | 685.8 |  |  | $ | 262.5 |  |  | $ | 253.0 |
Benefit obligations | (973.1 | ) |  | (931.6 | ) |  | (265.9 | ) |  | (264.6 | )
Amount recognized at December 31 | $ | (223.3 | ) |  | $ | (245.8 | ) |  | $ | (3.4 | ) |  | $ | (11.6 | )
Amounts recognized in Statements of Financial Position: |  |  |  |  |  |  |
Noncurrent assets | $ | — |  |  | $ | — |  |  | $ | 35.4 |  |  | $ | 27.3 |
Current liabilities | (0.5 | ) |  | (0.1 | ) |  | (3.9 | ) |  | (4.1 | )
Noncurrent liabilities | (222.8 | ) |  | (245.7 | ) |  | (34.9 | ) |  | (34.8 | )
Total amount recognized | $ | (223.3 | ) |  | $ | (245.8 | ) |  | $ | (3.4 | ) |  | $ | (11.6 | )
Amounts recognized in accumulated other comprehensive loss: |  |  |  |  |  |  |
Net actuarial loss | $ | 318.7 |  |  | $ | 315.9 |  |  | $ | 88.3 |  |  | $ | 87.0 |
Prior service cost (credit) | 8.8 |  |  | 11.0 |  |  | (25.6 | ) |  | (26.9 | )
Net amount recognized | $ | 327.5 |  |  | $ | 326.9 |  |  | $ | 62.7 |  |  | $ | 60.1 |
The estimated amounts that will be amortized from accumulated other comprehensive loss into net periodic benefit cost in 2018: |  |  |  |  |  |  |
Net actuarial loss | $ | 21.1 |  |  |  |  | $ | 4.9 |  |  |
Prior service cost (credit) | 2.2 |  |  |  |  | (3.0 | ) |  |
Net amount recognized | $ | 23.3 |  |  |  |  | $ | 1.9 |  |  |
Fair Value Of Plan Assets, Benefit Obligation And Funded Status |
| (In Millions)
| 2017
| Pension Plans |  | Other Benefits
| Salaried |  | Hourly |  | Mining |  | SERP |  | Total |  | Salaried |  | Hourly |  | Total
Fair value of plan assets | $ | 269.4 |  |  | $ | 473.0 |  |  | $ | 7.4 |  |  | $ | — |  |  | $ | 749.8 |  |  | $ | — |  |  | $ | 262.5 |  |  | $ | 262.5 |
Benefit obligation | (368.0 | ) |  | (590.0 | ) |  | (10.3 | ) |  | (4.8 | ) |  | (973.1 | ) |  | (37.7 | ) |  | (228.2 | ) |  | (265.9 | )
Funded status | $ | (98.6 | ) |  | $ | (117.0 | ) |  | $ | (2.9 | ) |  | $ | (4.8 | ) |  | $ | (223.3 | ) |  | $ | (37.7 | ) |  | $ | 34.3 |  |  | $ | (3.4 | )
| 2016
| Pension Plans |  | Other Benefits
| Salaried |  | Hourly |  | Mining |  | SERP |  | Total |  | Salaried |  | Hourly |  | Total
Fair value of plan assets | $ | 242.9 |  |  | $ | 436.9 |  |  | $ | 6.0 |  |  | $ | — |  |  | $ | 685.8 |  |  | $ | — |  |  | $ | 253.0 |  |  | $ | 253.0 |
Benefit obligation | (351.9 | ) |  | (565.6 | ) |  | (10.0 | ) |  | (4.1 | ) |  | (931.6 | ) |  | (37.6 | ) |  | (227.0 | ) |  | (264.6 | )
Funded status | $ | (109.0 | ) |  | $ | (128.7 | ) |  | $ | (4.0 | ) |  | $ | (4.1 | ) |  | $ | (245.8 | ) |  | $ | (37.6 | ) |  | $ | 26.0 |  |  | $ | (11.6 | )
Components Of Net Periodic Benefit Cost | Components of Net Periodic Benefit Cost
| (In Millions)
| Pension Benefits |  | Other Benefits
| 2017 |  | 2016 |  | 2015 |  | 2017 |  | 2016 |  | 2015
Service cost | $ | 17.1 |  |  | $ | 17.6 |  |  | $ | 22.7 |  |  | $ | 1.8 |  |  | $ | 1.7 |  |  | $ | 6.4 |
Interest cost | 30.5 |  |  | 30.3 |  |  | 37.7 |  |  | 8.3 |  |  | 9.1 |  |  | 13.4 |
Expected return on plan assets | (54.5 | ) |  | (54.7 | ) |  | (59.8 | ) |  | (17.7 | ) |  | (17.1 | ) |  | (18.3 | )
Amortization: |  |  |  |  |  |  |  |  |  |  |
Prior service costs (credits) | 2.6 |  |  | 2.2 |  |  | 2.3 |  |  | (3.0 | ) |  | (3.7 | ) |  | (3.7 | )
Net actuarial loss | 22.3 |  |  | 21.1 |  |  | 20.8 |  |  | 4.5 |  |  | 6.0 |  |  | 6.6 |
Curtailments and settlements | — |  |  | — |  |  | 0.2 |  |  | — |  |  | — |  |  | — |
Net periodic benefit cost (credit) | $ | 18.0 |  |  | $ | 16.5 |  |  | $ | 23.9 |  |  | $ | (6.1 | ) |  | $ | (4.0 | ) |  | $ | 4.4 |
Curtailment effects | — |  |  | — |  |  | (1.2 | ) |  | — |  |  | — |  |  | — |
Current year actuarial loss (gain) | 9.3 |  |  | 37.8 |  |  | (0.7 | ) |  | 1.2 |  |  | (8.1 | ) |  | 0.2 |
Amortization of net loss | (22.3 | ) |  | (21.1 | ) |  | (21.0 | ) |  | (4.5 | ) |  | (6.0 | ) |  | (6.6 | )
Current year prior service cost | — |  |  | 5.7 |  |  | — |  |  | — |  |  | 9.8 |  |  | — |
Amortization of prior service credit (cost) | (2.6 | ) |  | (2.2 | ) |  | (2.3 | ) |  | 3.0 |  |  | 3.7 |  |  | 3.7 |
Total recognized in other comprehensive income (loss) | $ | (15.6 | ) |  | $ | 20.2 |  |  | $ | (25.2 | ) |  | $ | (0.3 | ) |  | $ | (0.6 | ) |  | $ | (2.7 | )
Total recognized in net periodic cost and other comprehensive income (loss) | $ | 2.4 |  |  | $ | 36.7 |  |  | $ | (1.3 | ) |  | $ | (6.4 | ) |  | $ | (4.6 | ) |  | $ | 1.7 |
Additional Information |
Weighted-Average Assumptions Used to Determine Benefit Obligations | Weighted-average assumptions used to determine benefit obligations at December 31 were:
| Pension Benefits |  | Other Benefits
| 2017 |  | 2016 |  | 2017 |  | 2016
Discount rate |  |  |  |  |  |  |  |  |  |  |
Iron Hourly Pension Plan | 3.60 | % |  | 4.02 | % |  | N/A | % |  | N/A | %
Salaried Pension Plan | 3.52 |  |  | 3.92 |  |  | N/A |  |  | N/A |
Ore Mining Pension Plan | 3.61 |  |  | 4.04 |  |  | N/A |  |  | N/A |
SERP | 3.50 |  |  | 3.90 |  |  | N/A |  |  | N/A |
Hourly OPEB Plan | N/A |  |  | N/A |  |  | 3.60 |  |  | 4.02 |
Salaried OPEB Plan | N/A |  |  | N/A |  |  | 3.57 |  |  | 3.99 |
Salaried rate of compensation increase | 3.00 |  |  | 3.00 |  |  | 3.00 |  |  | 3.00 |
Hourly rate of compensation increase | 2.00 |  |  | 2.00 |  |  | N/A |  |  | N/A |
Weighted-Average Assumptions Used To Determine Net Benefit Costs | Weighted-average assumptions used to determine net benefit cost for the years 2017, 2016 and 2015 were:
| Pension Benefits |  | Other Benefits
| 2017 |  | 2016 |  | 2015 |  | 2017 |  | 2016 |  | 2015
Obligation Discount Rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Iron Hourly Pension Plan | 4.02 | % |  | 4.27 | % |  | 3.83 | % |  | N/A | % |  | N/A | % |  | N/A | %
Salaried Pension Plan | 3.91 |  |  | 4.13 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
Ore Mining Pension Plan | 4.04 |  |  | 4.28 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
SERP | 3.90 |  |  | 4.01 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
Hourly OPEB Plan | N/A |  |  | N/A |  |  | N/A |  |  | 4.03 |  |  | 4.32 |  |  | 3.83 |
Salaried OPEB Plan | N/A |  |  | N/A |  |  | N/A |  |  | 3.98 |  |  | 4.22 |  |  | 3.83 |
Service Cost Discount Rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Iron Hourly Pension Plan | 4.30 |  |  | 4.66 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
Salaried Pension Plan | 3.93 |  |  | 4.14 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
Ore Mining Pension Plan | 4.27 |  |  | 4.60 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
SERP | 3.69 |  |  | 3.87 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
Hourly OPEB Plan | N/A |  |  | N/A |  |  | N/A |  |  | 4.23 |  |  | 4.56 |  |  | 3.83 |
Salaried OPEB Plan | N/A |  |  | N/A |  |  | N/A |  |  | 4.30 |  |  | 4.63 |  |  | 3.83 |
Interest Cost Discount Rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Iron Hourly Pension Plan | 3.38 |  |  | 3.46 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
Salaried Pension Plan | 3.21 |  |  | 3.21 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
Ore Mining Pension Plan | 3.41 |  |  | 3.48 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
SERP | 3.36 |  |  | 3.30 |  |  | 3.83 |  |  | N/A |  |  | N/A |  |  | N/A |
Hourly OPEB Plan | N/A |  |  | N/A |  |  | N/A |  |  | 3.24 |  |  | 3.48 |  |  | 3.83 |
Salaried OPEB Plan | N/A |  |  | N/A |  |  | N/A |  |  | 3.28 |  |  | 3.31 |  |  | 3.83 |
Expected return on plan assets | 8.25 |  |  | 8.25 |  |  | 8.25 |  |  | 7.00 |  |  | 7.00 |  |  | 7.00 |
Salaried rate of compensation increase | 3.00 |  |  | 3.00 |  |  | 3.00 |  |  | 3.00 |  |  | 3.00 |  |  | 3.00 |
Hourly rate of compensation increase | 2.00 |  |  | 2.00 |  |  | 2.50 |  |  | N/A |  |  | N/A |  |  | N/A |
Assumed Health Care Cost Trend Rates | Assumed health care cost trend rates at December 31 were:
| 2017 |  | 2016
Health care cost trend rate assumed for next year | 7.00 | % |  | 6.50 | %
Ultimate health care cost trend rate | 5.00 |  |  | 5.00 |
Year that the ultimate rate is reached | 2026 |  |  | 2023 |
Effect of One Percentage Point Change in Assumed Health Care Cost Trend Rates | A change of one percentage point in assumed health care cost trend rates would have the following effects:
| (In Millions)
| Increase |  | Decrease
Effect on total of service and interest cost | $ | 1.0 |  |  | $ | (0.8 | )
Effect on postretirement benefit obligation | 21.2 |  |  | (17.6 | )
Plan Assets and Asset Allocation | The following table reflects the actual asset allocations for pension and VEBA plan assets as of December 31, 2017 and 2016, as well as the 2018 weighted average target asset allocations. Equity investments include securities in large-cap, mid-cap and small-cap companies located in the U.S. and worldwide. Fixed income investments primarily include corporate bonds and government debt securities. Alternative investments include hedge funds, private equity, structured credit and real estate.
| Pension Assets |  | VEBA Assets
Asset Category | 2018 Target Allocation |  | Percentage of Plan Assets at December 31, |  | 2018 Target Allocation |  | Percentage of Plan Assets at December 31,
2017 |  | 2016 |  | 2017 |  | 2016
Equity securities | 45.0 | % |  | 43.6 | % |  | 43.2 | % |  | 8.0 | % |  | 8.7 | % |  | 8.4 | %
Fixed income | 28.0 | % |  | 27.0 | % |  | 26.4 | % |  | 80.0 | % |  | 77.7 | % |  | 78.3 | %
Hedge funds | 5.0 | % |  | 5.0 | % |  | 5.9 | % |  | 4.0 | % |  | 4.4 | % |  | 4.4 | %
Private equity | 7.0 | % |  | 5.3 | % |  | 5.3 | % |  | 3.0 | % |  | 1.5 | % |  | 1.7 | %
Structured credit | 7.5 | % |  | 9.7 | % |  | 9.3 | % |  | 2.0 | % |  | 3.0 | % |  | 2.7 | %
Real estate | 7.5 | % |  | 8.7 | % |  | 9.0 | % |  | 3.0 | % |  | 4.6 | % |  | 4.4 | %
Cash | — | % |  | 0.7 | % |  | 0.9 | % |  | — | % |  | 0.1 | % |  | 0.1 | %
Total | 100.0 | % |  | 100.0 | % |  | 100.0 | % |  | 100.0 | % |  | 100.0 | % |  | 100.0 | %
Fair Value, Assets and Liabilities Measured on Recurring Basis | Pension The fair values of our pension plan assets at December 31, 2017 and 2016 by asset category are as follows:
| (In Millions)
| December 31, 2017
Asset Category | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total
Equity securities: |  |  |  |  |  |  |
U.S. large-cap | $ | 130.1 |  |  | $ | — |  |  | $ | — |  |  | $ | 130.1 |
U.S. small/mid-cap | 35.5 |  |  | — |  |  | — |  |  | 35.5 |
International | 160.9 |  |  | — |  |  | — |  |  | 160.9 |
Fixed income | 173.6 |  |  | 28.8 |  |  | — |  |  | 202.4 |
Hedge funds | — |  |  | — |  |  | 37.4 |  |  | 37.4 |
Private equity | — |  |  | — |  |  | 39.8 |  |  | 39.8 |
Structured credit | — |  |  | — |  |  | 72.9 |  |  | 72.9 |
Real estate | — |  |  | — |  |  | 65.5 |  |  | 65.5 |
Cash | 5.3 |  |  | — |  |  | — |  |  | 5.3 |
Total | $ | 505.4 |  |  | $ | 28.8 |  |  | $ | 215.6 |  |  | $ | 749.8 |
| (In Millions)
| December 31, 2016
Asset Category | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total
Equity securities: |  |  |  |  |  |  |
U.S. large-cap | $ | 144.7 |  |  | $ | — |  |  | $ | — |  |  | $ | 144.7 |
U.S. small/mid-cap | 39.9 |  |  | — |  |  | — |  |  | 39.9 |
International | 111.8 |  |  | — |  |  | — |  |  | 111.8 |
Fixed income | 157.5 |  |  | 23.7 |  |  | — |  |  | 181.2 |
Hedge funds | — |  |  | — |  |  | 40.6 |  |  | 40.6 |
Private equity | — |  |  | — |  |  | 36.1 |  |  | 36.1 |
Structured credit | — |  |  | — |  |  | 63.8 |  |  | 63.8 |
Real estate | — |  |  | — |  |  | 61.9 |  |  | 61.9 |
Cash | 5.8 |  |  | — |  |  | — |  |  | 5.8 |
Total | $ | 459.7 |  |  | $ | 23.7 |  |  | $ | 202.4 |  |  | $ | 685.8 |
Effect of Fair Value Measurements Using Significant Unobservable Inputs on Changes in Plan Assets | The following represents the effect of fair value measurements using significant unobservable inputs (Level 3) on changes in plan assets for the years ended December 31, 2017 and 2016:
| (In Millions)
| Year Ended December 31, 2017
| Hedge Funds |  | Private Equity Funds |  | Structured Credit Fund |  | Real Estate |  | Total
Beginning balance — January 1, 2017 | $ | 40.6 |  |  | $ | 36.1 |  |  | $ | 63.8 |  |  | $ | 61.9 |  |  | $ | 202.4 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |
Relating to assets still held at the reporting date | 2.5 |  |  | 0.3 |  |  | 9.1 |  |  | 4.2 |  |  | 16.1 |
Relating to assets sold during the period | 0.4 |  |  | 4.5 |  |  | — |  |  | (0.1 | ) |  | 4.8 |
Purchases | 39.0 |  |  | 4.5 |  |  | — |  |  | 14.4 |  |  | 57.9 |
Sales | (45.1 | ) |  | (5.6 | ) |  | — |  |  | (14.9 | ) |  | (65.6 | )
Ending balance — December 31, 2017 | $ | 37.4 |  |  | $ | 39.8 |  |  | $ | 72.9 |  |  | $ | 65.5 |  |  | $ | 215.6 |
| (In Millions)
| Year Ended December 31, 2016
| Hedge Funds |  | Private Equity Funds |  | Structured Credit Fund |  | Real Estate |  | Total
Beginning balance — January 1, 2016 | $ | 40.7 |  |  | $ | 33.1 |  |  | $ | 62.1 |  |  | $ | 57.5 |  |  | $ | 193.4 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |
Relating to assets still held at the reporting date | (0.1 | ) |  | (2.7 | ) |  | 10.0 |  |  | 5.1 |  |  | 12.3 |
Relating to assets sold during the period | — |  |  | 3.7 |  |  | (0.3 | ) |  | (0.1 | ) |  | 3.3 |
Purchases | — |  |  | 8.0 |  |  | — |  |  | — |  |  | 8.0 |
Sales | — |  |  | (6.0 | ) |  | (8.0 | ) |  | (0.6 | ) |  | (14.6 | )
Ending balance — December 31, 2016 | $ | 40.6 |  |  | $ | 36.1 |  |  | $ | 63.8 |  |  | $ | 61.9 |  |  | $ | 202.4 |
VEBA Assets fo
Schedule Of Annual Contributions |
|  | (In Millions)
|  | Pension Benefits |  | Other Benefits
Company Contributions |  | VEBA |  | Direct Payments |  | Total
2016 |  | $ | 1.2 |  |  | $ | — |  |  | $ | 1.1 |  |  | $ | 1.1 |
2017 |  | 24.4 |  |  | — |  |  | 2.1 |  |  | 2.1 |
2018 (Expected)1 |  | 27.8 |  |  | — |  |  | 4.0 |  |  | 4.0 |
1 Pursuant to the bargaining agreement, benefits can be paid from VEBA trusts that are at least 70% funded (all VEBA trusts are over 70% funded at December 31, 2017). Funding obligations have been suspended as Hibbing's, UTAC's, Tilden's and Empire's share of the value of their respective trust assets have reached 90% of their obligation.
Estimated Net Periodic Benefit Cost | Estimated Cost for 2018 For 2018, we estimate net periodic benefit cost as follows:
| (In Millions)
Defined benefit pension plans | $ | 12.3 |
Other postretirement benefits | (6.2 | )
Total | $ | 6.1 |
Estimated Future Benefit Payments | Estimated Future Benefit Payments
| (In Millions)
| Pension Benefits |  | Other Benefits
Gross Company Benefits |  | Less Medicare Subsidy |  | Net Benefit Payments
2018 | $ | 69.6 |  |  | $ | 18.9 |  |  | $ | (0.7 | ) |  | $ | 18.2 |
2019 | 66.7 |  |  | 18.0 |  |  | (0.8 | ) |  | 17.2 |
2020 | 66.0 |  |  | 17.4 |  |  | (0.9 | ) |  | 16.5 |
2021 | 65.1 |  |  | 16.9 |  |  | (1.0 | ) |  | 15.9 |
2022 | 65.2 |  |  | 16.7 |  |  | (1.1 | ) |  | 15.6 |
2023-2027 | 310.5 |  |  | 81.5 |  |  | (6.6 | ) |  | 74.9 |
Veba Trust [Member] |
Defined Benefit Plan Disclosure [Line Items] |
Fair Value, Assets and Liabilities Measured on Recurring Basis | The fair value of our other benefit plan assets at December 31, 2017 and 2016 by asset category are as follows:
| (In Millions)
| December 31, 2017
Asset Category | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total
Equity securities: |  |  |  |  |  |  |
U.S. large-cap | $ | 11.4 |  |  | $ | — |  |  | $ | — |  |  | $ | 11.4 |
U.S. small/mid-cap | 2.8 |  |  | — |  |  | — |  |  | 2.8 |
International | 8.8 |  |  | — |  |  | — |  |  | 8.8 |
Fixed income | 164.1 |  |  | 40.0 |  |  | — |  |  | 204.1 |
Hedge funds | — |  |  | — |  |  | 11.4 |  |  | 11.4 |
Private equity | — |  |  | — |  |  | 3.9 |  |  | 3.9 |
Structured credit | — |  |  | — |  |  | 7.9 |  |  | 7.9 |
Real estate | — |  |  | — |  |  | 12.0 |  |  | 12.0 |
Cash | 0.2 |  |  | — |  |  | — |  |  | 0.2 |
Total | $ | 187.3 |  |  | $ | 40.0 |  |  | $ | 35.2 |  |  | $ | 262.5 |
| (In Millions)
| December 31, 2016
Asset Category | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) |  | Significant Other Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total
Equity securities: |  |  |  |  |  |  |
U.S. large-cap | $ | 10.6 |  |  | $ | — |  |  | $ | — |  |  | $ | 10.6 |
U.S. small/mid-cap | 2.7 |  |  | — |  |  | — |  |  | 2.7 |
International | 8.1 |  |  | — |  |  | — |  |  | 8.1 |
Fixed income | 162.0 |  |  | 35.9 |  |  | — |  |  | 197.9 |
Hedge funds | — |  |  | — |  |  | 11.2 |  |  | 11.2 |
Private equity | — |  |  | — |  |  | 4.3 |  |  | 4.3 |
Structured credit | — |  |  | — |  |  | 6.9 |  |  | 6.9 |
Real estate | — |  |  | — |  |  | 11.1 |  |  | 11.1 |
Cash | 0.2 |  |  | — |  |  | — |  |  | 0.2 |
Total | $ | 183.6 |  |  | $ | 35.9 |  |  | $ | 33.5 |  |  | $ | 253.0 |
Effect of Fair Value Measurements Using Significant Unobservable Inputs on Changes in Plan Assets | The following represents the effect of fair value measurements using significant unobservable inputs (Level 3) on changes in plan assets for the year ended December 31, 2017 and 2016:
| (In Millions)
| Year Ended December 31, 2017
| Hedge Funds |  | Private Equity Funds |  | Structured Credit Fund |  | Real Estate |  | Total
Beginning balance — January 1, 2017 | $ | 11.2 |  |  | $ | 4.3 |  |  | $ | 6.9 |  |  | $ | 11.1 |  |  | $ | 33.5 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |
Relating to assets still held at the reporting date | 0.8 |  |  | 0.9 |  |  | 2.0 |  |  | 3.4 |  |  | 7.1 |
Relating to assets sold during the period | — |  |  | (0.4 | ) |  | (1.0 | ) |  | (2.5 | ) |  | (3.9 | )
Purchases | 17.1 |  |  | 1.8 |  |  | 2.1 |  |  | 3.0 |  |  | 24.0 |
Sales | (17.7 | ) |  | (2.7 | ) |  | (2.1 | ) |  | (3.0 | ) |  | (25.5 | )
Ending balance — December 31, 2017 | $ | 11.4 |  |  | $ | 3.9 |  |  | $ | 7.9 |  |  | $ | 12.0 |  |  | $ | 35.2 |
| (In Millions)
| Year Ended December 31, 2016
| Hedge Funds |  | Private Equity Funds |  | Structured Credit Fund |  | Real Estate |  | Total
Beginning balance — January 1, 2016 | $ | 11.2 |  |  | $ | 5.5 |  |  | $ | 5.8 |  |  | $ | 10.0 |  |  | $ | 32.5 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |
Relating to assets still held at the reporting date | — |  |  | (0.3 | ) |  | 1.1 |  |  | 1.1 |  |  | 1.9 |
Relating to assets sold during the period | — |  |  | 0.1 |  |  | — |  |  | — |  |  | 0.1 |
Purchases | — |  |  | — |  |  | — |  |  | — |  |  | — |
Sales | — |  |  | (1.0 | ) |  | — |  |  | — |  |  | (1.0 | )
Ending balance — December 31, 2016 | $ | 11.2 |  |  | $ | 4.3 |  |  | $ | 6.9 |  |  | $ | 11.1 |  |  | $ | 33.5 |
Contributions

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