| Compensation and Retirement Disclosure [Abstract] | Period [Axis] |
|---|
2016-01-01 - 2016-12-31 |
|---|
Compensation and Retirement Disclosure [Abstract] | |
Schedule of Weighted-Average and Target Asset Allocations | The Company’s weighted-average asset allocations at December 31, 2016 and 2015, and 2016 year-end target allocation, by asset category, were as follows: | | | | | | | | | | | Target | | 2016 | | 2015 | Domestic equity securities | 34 | % | | 31 | % | | 34 | % | International equity securities | 18 | % | | 20 | % | | 18 | % | Fixed income securities | 36 | % | | 35 | % | | 35 | % | Other | 12 | % | | 9 | % | | 10 | % | Cash | — | % | | 5 | % | | 3 | % | Total | 100 | % | | 100 | % | | 100 | % |
|
Schedule of Fair Value of Pension Plan Assets by Asset Category | The fair values of the Company’s pension plan assets at December 31, 2016 and 2015, by asset category, are as follows (in millions): | | | | | | | | | | | | | | | | | | Fair Value Measurements as of | | December 31, 2016 | | Total | | Quoted Prices in Active Markets (Level 1) | | Significant Observable Inputs (Level 2) | | Significant Unobservable Inputs (Level 3) | Asset Category | | | | | | | | Cash | $ | 6.1 |
| | $ | 6.1 |
| | $ | — |
| | $ | — |
| Equity securities: | | | | | | | | Domestic | 28.1 |
| | 28.1 |
| | — |
| | — |
| Domestic exchange-traded funds | 16.9 |
| | 16.9 |
| | — |
| | — |
| International | 24.5 |
| | 24.5 |
| | — |
| | — |
| International and emerging markets exchange-traded funds | 4.1 |
| | 4.1 |
| | — |
| | — |
| Fixed income securities: | | | | | | | | U.S. Treasury obligations | 21.7 |
| | 21.7 |
| | — |
| | — |
| Domestic corporate bonds and notes | 26.6 |
| | — |
| | 26.6 |
| | — |
| Foreign corporate bonds | 1.5 |
| | — |
| | 1.5 |
| | — |
| Other types of investments: | | | | | | | | Limited partnership interest in private equity fund | 0.1 |
| | — |
| | — |
| | 0.1 |
| Exchange-traded global real estate securities | 9.9 |
| | 9.9 |
| | — |
| | — |
| Insurance contracts | 0.1 |
| | — |
| | — |
| | 0.1 |
| Exchange-traded commodity fund | 2.9 |
| | 2.9 |
| | — |
| | — |
| Other receivables | 0.6 |
| | 0.6 |
| | — |
| | — |
| Total | $ | 143.1 |
| | $ | 114.8 |
| | $ | 28.1 |
| | $ | 0.2 |
|
| | | | | | | | | | | | | | | | | | Fair Value Measurements as of | | December 31, 2015 | | Total | | Quoted Prices in Active Markets (Level 1) | | Significant Observable Inputs (Level 2) | | Significant Unobservable Inputs (Level 3) | Asset Category | | | | | | | | Cash | $ | 3.8 |
| | $ | 3.8 |
| | $ | — |
| | $ | — |
| Equity securities: | | | | | | | | Domestic | 16.7 |
| | 16.7 |
| | — |
| | — |
| Domestic exchange-traded funds | 33.1 |
| | 33.1 |
| | | | | International | 18.6 |
| | 18.6 |
| | — |
| | — |
| International and emerging markets exchange-traded funds | 7.2 |
| | 7.2 |
| | — |
| | — |
| Fixed income securities: | | | | | | | | U.S. Treasury obligations | 17.1 |
| | 17.1 |
| | — |
| | — |
| Domestic corporate bonds and notes | 31.6 |
| | — |
| | 31.6 |
| | — |
| Foreign corporate bonds | 3.1 |
| | — |
| | 3.1 |
| | — |
| Other types of investments: | | | | | | | | Limited partnership interest in private equity fund | 0.2 |
| | — |
| | — |
| | 0.2 |
| Exchange-traded global real estate securities | 11.2 |
| | 11.2 |
| | — |
| | — |
| Insurance contracts | 0.2 |
| | — |
| | — |
| | 0.2 |
| Exchange-traded commodity fund | 2.7 |
| | 2.7 |
| | — |
| | — |
| Other receivables | 0.7 |
| | 0.7 |
| | — |
| | — |
| Total | $ | 146.2 |
| | $ | 111.1 |
| | $ | 34.7 |
| | $ | 0.4 |
|
|
Schedule of Reconciliations of Pension Plan Investments Measured at Fair Value on a Recurring Basis | The table below presents a reconciliation of all pension plan investments measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2016 and 2015 (in millions): | | | | | | | | | | | | | | Fair Value Measurements Using Significant | | Unobservable Inputs (Level 3) | | Private Equity | | Insurance | | Total | Beginning balance, January 1, 2015 | $ | 0.3 |
| | $ | 1.4 |
| | $ | 1.7 |
| Actual return on plan assets: | | | | | | Assets held at the reporting date | (0.1 | ) | | 0.1 |
| | — |
| Assets sold during the period | — |
| | (1.3 | ) | | (1.3 | ) | Ending balance, December 31, 2015 | 0.2 |
| | 0.2 |
| | 0.4 |
| Actual return on plan assets: | | | | | | Assets held at the reporting date | (0.1 | ) | | (0.1 | ) | | (0.2 | ) | Ending balance, December 31, 2016 | $ | 0.1 |
| | $ | 0.1 |
| | $ | 0.2 |
|
|
Schedule of the Status of Funded Defined Benefit Pension Plan and Unfunded Accumulated Post-retirement Benefit Plans | The status of the funded defined benefit pension plan and the unfunded accumulated post-retirement benefit plans at December 31, 2016 and 2015 are shown below (in millions): | | | | | | | | | | | | | | | | | | Pension Benefits | | Other Post-retirement Benefits | | 2016 | | 2015 | | 2016 | | 2015 | Change in Benefit Obligation | | | | | | | | Benefit obligation at beginning of year | $ | 194.6 |
| | $ | 204.4 |
| | $ | 12.2 |
| | $ | 12.0 |
| Service cost | 3.1 |
| | 3.1 |
| | 0.1 |
| | 0.1 |
| Interest cost | 8.5 |
| | 8.0 |
| | 0.5 |
| | 0.5 |
| Plan participants’ contributions | — |
| | — |
| | 1.1 |
| | 0.9 |
| Actuarial (gain) loss | 4.7 |
| | (8.9 | ) | | — |
| | 0.4 |
| Benefits paid | (13.0 | ) | | (12.0 | ) | | (2.1 | ) | | (1.8 | ) | Conversion of guaranteed annuity contract | — |
| | (0.4 | ) | | — |
| | — |
| Curtailment | (0.9 | ) | | — |
| | 0.1 |
| | 0.1 |
| Amendments | — |
| | 0.4 |
| | — |
| | — |
| Benefit obligation at end of year | $ | 197.0 |
| | $ | 194.6 |
| | $ | 11.9 |
| | $ | 12.2 |
| Change in Plan Assets | | | | | | | | Fair value of plan assets at beginning of year | 146.2 |
| | 160.8 |
| | — |
| | — |
| Actual return on plan assets | 9.4 |
| | (4.8 | ) | | — |
| | — |
| Employer contributions | 0.5 |
| | 2.6 |
| | 0.9 |
| | 0.8 |
| Participant contributions | — |
| | — |
| | 1.1 |
| | 0.9 |
| Conversion of guaranteed annuity contract | — |
| | (0.4 | ) | | — |
| | — |
| Benefits paid | (13.0 | ) | | (12.0 | ) | | (2.1 | ) | | (1.8 | ) | Other | — |
| | — |
| | 0.1 |
| | 0.1 |
| Fair value of plan assets at end of year | $ | 143.1 |
| | $ | 146.2 |
| | $ | — |
| | $ | — |
| | | | | | | | | Funded Status and Recognized Liability | $ | (53.9 | ) | | $ | (48.4 | ) | | $ | (11.9 | ) | | $ | (12.2 | ) |
|
Summary of Amounts Recognized on the Consolidated Balance Sheets and in Accumulated Other Comprehensive Loss | Amounts recognized on the consolidated balance sheets and in accumulated other comprehensive loss at December 31, 2016 and 2015 were as follows (in millions): | | | | | | | | | | | | | | | | | | Pension Benefits | | Other Post-retirement Benefits | | 2016 | | 2015 | | 2016 | | 2015 | Current liabilities | — |
| | — |
| | (1.0 | ) | | (0.9 | ) | Non-current liabilities | (53.9 | ) | | (48.4 | ) | | (10.9 | ) | | (11.3 | ) | Total | $ | (53.9 | ) | | $ | (48.4 | ) | | $ | (11.9 | ) | | $ | (12.2 | ) | | | | | | | | | Net loss (net of taxes) | $ | 45.6 |
| | $ | 47.3 |
| | $ | 0.6 |
| | $ | 0.6 |
| Unrecognized prior service credit (net of taxes) | (1.8 | ) | | (2.6 | ) | | — |
| | — |
| Total | $ | 43.8 |
| | $ | 44.7 |
| | $ | 0.6 |
| | $ | 0.6 |
|
|
Summary of Information for Qualified Pension Plans with an Accumulated Benefit Obligation in Excess of Plan Assets | The information for qualified pension plans with an accumulated benefit obligation in excess of plan assets at December 31, 2016 and 2015 is shown below (in millions): | | | | | | | | | | 2016 | | 2015 | Projected benefit obligation | $ | 197.0 |
| | $ | 194.6 |
| Accumulated benefit obligation | $ | 197.0 |
| | $ | 193.7 |
| Fair value of plan assets | $ | 143.1 |
| | $ | 146.2 |
|
|
Summary of Components of Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Loss | Components of the net periodic benefit cost and other amounts recognized in other comprehensive income (loss) for the defined benefit pension plans and the post-retirement health care and life insurance benefit plans during 2016, 2015, and 2014, are shown below (in millions): | | | | | | | | | | | | | | | | | | | | | | | | | | Pension Benefits | | Other Post-retirement Benefits | | 2016 | | 2015 | | 2014 | | 2016 | | 2015 | | 2014 | Components of Net Periodic Benefit Cost | | | | | | | | | | | | Service cost | $ | 3.1 |
| | $ | 3.1 |
| | $ | 2.6 |
| | $ | 0.1 |
| | $ | 0.1 |
| | $ | 0.1 |
| Interest cost | 8.5 |
| | 8.0 |
| | 8.3 |
| | 0.5 |
| | 0.5 |
| | 0.6 |
| Expected return on plan assets | (10.0 | ) | | (11.1 | ) | | (10.7 | ) | | — |
| | — |
| | — |
| Amortization of net loss | 7.1 |
| | 6.9 |
| | 4.0 |
| | 0.2 |
| | 0.1 |
| | 0.3 |
| Amortization of prior service cost | (0.5 | ) | | (0.8 | ) | | (0.8 | ) | | — |
| | — |
| | — |
| Curtailment (gain)/loss | (0.9 | ) | | — |
| | — |
| | — |
| | 0.1 |
| | — |
| Net periodic benefit cost | 7.3 |
| | 6.1 |
| | 3.4 |
| | 0.8 |
| | 0.8 |
| | 1.0 |
| | | | | | | | | | | | | Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) | | | | | | | | | | | | Net loss (gain) | $ | 4.4 |
| | $ | 7.0 |
| | $ | 27.1 |
| | $ | — |
| | $ | 0.4 |
| | $ | (0.6 | ) | Amortization of unrecognized gain (loss) | (7.1 | ) | | (6.9 | ) | | (4.0 | ) | | (0.2 | ) | | (0.1 | ) | | (0.3 | ) | Amortization of prior service credit | 1.4 |
| | 0.8 |
| | 0.8 |
| | — |
| | — |
| | — |
| Prior service cost | — |
| | 0.4 |
| | — |
| | — |
| | — |
| | — |
| Total recognized in other comprehensive income (loss) | (1.3 | ) | | 1.3 |
| | 23.9 |
| | (0.2 | ) | | 0.3 |
| | (0.9 | ) | Total recognized in net periodic benefit cost and other comprehensive income | $ | 6.0 |
| | $ | 7.4 |
| | $ | 27.3 |
| | $ | 0.6 |
| | $ | 1.1 |
| | $ | 0.1 |
|
|
Summary of Weighted Average Assumptions used to Determine Benefit Information | The weighted average assumptions used to determine benefit information during 2016, 2015 and 2014 were as follows: | | | | | | | | | | | | | | | | | | | | Pension Benefits | | Other Post-retirement Benefits | | 2016 | | 2015 | | 2014 | | 2016 | | 2015 | | 2014 | Weighted Average Assumptions: | | | | | | | | | | | | Discount rate | 4.20 | % | | 4.50 | % | | 4.00 | % | | 4.20 | % | | 4.50 | % | | 4.10 | % | Expected return on plan assets | 7.10 | % | | 7.10 | % | | 7.10 | % | | — | % | | — | % | | — | % | Rate of compensation increase | 0.5%-3% |
| | 0.5%-3% |
| | 0.5%-3% |
| | 0.5%-3% |
| | 0.5%-3% |
| | 3.00 | % | Initial health care cost trend rate | | | | | | | 6.80 | % | | 7.00 | % | | 7.30 | % | Ultimate rate | | | | | | | 4.50 | % | | 4.50 | % | | 4.50 | % | Year ultimate rate is reached | | | | | | | 2037 |
| | 2037 | | 2028 |
|
Summary of Effect of One-Percentage-Point Change in Accumulated Post-retirement Benefit Obligation | If the assumed health care cost trend rate were increased or decreased by one percentage point, the accumulated post-retirement benefit obligation, as of December 31, 2016, 2015 and 2014 and the net periodic post-retirement benefit cost for 2016, 2015 and 2014, would have increased or decreased as follows (in millions): | | | | | | | | | | | | | | | | | | | | | | | | | | Other Post-retirement Benefits | | One Percentage Point | | Increase | | Decrease | | 2016 | | 2015 | | 2014 | | 2016 | | 2015 | | 2014 | Effect on total of service and interest cost components | $ | 0.1 |
| | $ | 0.1 |
| | $ | 0.1 |
| | $ | — |
| | $ | — |
| | $ | (0.1 | ) | Effect on post-retirement benefit obligation | $ | 1.0 |
| | $ | 1.1 |
| | $ | 1.1 |
| | $ | (0.9 | ) | | $ | (0.9 | ) | | $ | (0.9 | ) |
|
Schedule of Estimated Future Benefit Payments for the Next Ten Years | The estimated future benefit payments for the next ten years are as follows (in millions): | | | | | | | | | | | | | | | | Pension | | Non-qualified | | Post-retirement | Year | | Benefits | | Plan Benefits | | Benefits | 2017 | | $ | 11.6 |
| | $ | 4.2 |
| | $ | 1.0 |
| 2018 | | $ | 11.8 |
| | $ | 1.7 |
| | $ | 1.0 |
| 2019 | | $ | 12.0 |
| | $ | 0.1 |
| | $ | 1.0 |
| 2020 | | $ | 12.2 |
| | $ | — |
| | $ | 1.0 |
| 2021 | | $ | 12.4 |
| | $ | — |
| | $ | 0.9 |
| 2022-2026 | | $ | 62.8 |
| | $ | 1.9 |
| | $ | 3.6 |
|
|
Schedule of Multiemployer Plans | There were no plans to which the Company contributed more than 5 percent of the total contributions. | | | | | | | | | | | | | | | | Pension Protection Act Zone Status | FIP/RP Status | Contribution by Entity | Contribution by Entity | Surcharge Imposed | Expiration Date | Current Plan Year End | | EIN Plan No. | 2016 and 2015 | Pending/Implemented | Jan. 1 - Dec. 31, 2016 | Jan. 1 - Dec. 31, 2015 | Fund | | | | | | | | | Operating Engineers | 94-6090764; 001 | Red | Yes | $ | 4.7 |
| $ | 4.6 |
| No | 9/2/19 | 12/31/16 | Laborers National | 52-6074345; 001 | Red | Yes | 0.1 |
| 0.1 |
| No | 8/31/18 | 12/31/16 | Hawaii Laborers | 99-6025107; 001 | Green | No | 0.7 |
| 0.8 |
| No | 8/31/19 | 2/29/16 | Hawaii Laborers | 99-6025107; 001 | Green | No | 0.2 |
| 0.2 |
| No | 9/30/19 | 2/29/16 | Total | | | | $ | 5.7 |
| $ | 5.7 |
| | | |
|