EMPLOYEE BENEFIT PLANS (Tables)
|
12 Months Ended |
Dec. 31, 2018 |
|---|
| Defined Benefit Plan Disclosure [Line Items] |
|
| Schedule of Changes in Projected Benefit Obligations [Table Text Block] |
The measurement date used to determine pension and other postretirement benefit obligations is December 31. Data related to the changes in the projected benefit obligation for pension benefits and the accumulated benefit obligation for other postretirement benefits are presented below. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | | | Pension Benefits |
| Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | Millions of dollars | | 2018 |
| 2017 |
| 2018 |
| 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Benefit obligation, January 1 | | $ | 933.2 |
| | $ | 904.3 |
| | $ | 289.2 |
| | $ | 274.7 |
| | $ | 793.0 |
| | $ | 768.4 |
| | $ | 216.6 |
| | $ | 207.2 |
| Service cost | | 21.0 |
| | 21.7 |
| | 4.6 |
| | 4.5 |
| | 17.1 |
| | 18.1 |
| | 3.6 |
| | 3.7 |
| Interest cost | | 34.1 |
| | 37.4 |
| | 10.1 |
| | 11.5 |
| | 29.0 |
| | 31.9 |
| | 8.0 |
| | 9.5 |
| Plan participants’ contributions | | — |
| | — |
| | 1.4 |
| | 1.3 |
| | — |
| | — |
| | 1.1 |
| | 1.1 |
| Actuarial (gain) loss | | (53.1 | ) | | 42.2 |
| | (38.4 | ) | | 9.7 |
| | (45.5 | ) | | 36.6 |
| | (30.7 | ) | | 6.8 |
| Benefits paid | | (71.7 | ) | | (72.4 | ) | | (13.2 | ) | | (12.5 | ) | | (61.3 | ) | | (62.0 | ) | | (10.4 | ) | | (10.3 | ) | Amounts funded to parent | | n/a |
| | n/a |
| | n/a |
| | n/a |
| | — |
| | — |
| | (0.8 | ) | | (1.4 | ) | Benefit obligation, December 31 | | $ | 863.5 |
| | $ | 933.2 |
| | $ | 253.7 |
| | $ | 289.2 |
| | $ | 732.3 |
| | $ | 793.0 |
| | $ | 187.4 |
| | $ | 216.6 |
|
|
| Schedule of Assumptions Used to Determine Benefit Obligations [Table Text Block] |
Significant assumptions used to determine the above benefit obligations are as follows: | | | | | | | | | | | | | | Pension Benefits | | Other Postretirement Benefits | | 2018 | | 2017 | | 2018 | | 2017 | Annual discount rate used to determine benefit obligation | 4.35 | % | | 3.71 | % | | 4.38 | % | | 3.74 | % | Assumed annual rate of future salary increases for projected benefit obligation | 3.00 | % | | 3.00 | % | | 3.00 | % | | 3.00 | % |
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| Schedule of Net Funded Status [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | December 31, | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Fair value of plan assets | | $ | 727.3 |
| | $ | 849.6 |
| | — |
| | — |
| | $ | 676.7 |
| | $ | 781.3 |
| | — |
| | — |
| Benefit obligation | | 863.5 |
| | 933.2 |
| | $ | 253.7 |
| | $ | 289.2 |
| | 732.3 |
| | 793.0 |
| | $ | 187.4 |
| | $ | 216.6 |
| Funded status | | $ | (136.2 | ) | | $ | (83.6 | ) | | $ | (253.7 | ) | | $ | (289.2 | ) | | $ | (55.6 | ) | | $ | (11.7 | ) | | $ | (187.4 | ) | | $ | (216.6 | ) |
|
| Schedule of Amounts Recognized in Balance Sheet [Table Text Block] |
Amounts recognized on the consolidated balance sheets were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | December 31, | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Current liability | | — |
| | — |
| | $ | (13.3 | ) | | $ | (13.5 | ) | | — |
| | — |
| | $ | (10.5 | ) | | $ | (10.8 | ) | Noncurrent liability | | $ | (136.2 | ) | | $ | (83.6 | ) | | (240.4 | ) | | (275.7 | ) | | $ | (55.6 | ) | | $ | (11.7 | ) | | (176.9 | ) | | (205.8 | ) |
|
| Schedule of Defined Benefit Plan, Amounts Recognized in Accumulated Other Comprehensive Income (Loss) [Table Text Block] |
Other changes in plan assets and benefit obligations recognized in OCI (net of tax) were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Pension Benefits | | Other Postretirement Benefits | Millions of dollars | | 2018 | | 2017 | | 2016 | | 2018 | | 2017 | | 2016 | Current year actuarial (gain) loss | | $ | 4.5 |
| | $ | (1.0 | ) | | $ | 0.6 |
| | $ | (2.4 | ) | | $ | 1.1 |
| | $ | 0.8 |
| Amortization of actuarial losses | | (0.5 | ) | | (0.6 | ) | | (0.6 | ) | | — |
| | (0.1 | ) | | — |
| Amortization of prior service cost | | — |
| | — |
| | (0.1 | ) | | — |
| | — |
| | — |
| Total recognized in OCI | | $ | 4.0 |
| | $ | (1.6 | ) | | $ | (0.1 | ) | | $ | (2.4 | ) | | $ | 1.0 |
| | $ | 0.8 |
|
|
| Schedule of defined benefit plan, amounts recognized in regulatory assets [Table Text Block] |
Amounts recognized in regulatory assets were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | December 31, | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Net actuarial loss | | $ | 230.4 |
| | $ | 194.8 |
| | $ | 10.9 |
| | $ | 43.3 |
| | $ | 202.4 |
| | $ | 171.4 |
| | $ | 9.0 |
| | $ | 35.9 |
| Prior service cost | | 0.7 |
| | 1.2 |
| | — |
| | — |
| | 0.6 |
| | 1.0 |
| | — |
| | — |
| Total | | $ | 231.1 |
| | $ | 196.0 |
| | $ | 10.9 |
| | $ | 43.3 |
| | $ | 203.0 |
| | $ | 172.4 |
| | $ | 9.0 |
| | $ | 35.9 |
|
|
| Schedule of Changes in Fair Value of Plan Assets [Table Text Block] |
| | | | | | | | | | | | | | | | | | Pension Benefits
| | The Company | | Consolidated SCE&G | Millions of dollars | | 2018 | | 2017 | | 2018 | | 2017 | Fair value of plan assets, January 1 | | $ | 849.6 |
| | $ | 793.6 |
| | $ | 781.3 |
| | $ | 732.9 |
| Actual return (loss) on plan assets | | (50.6 | ) | | 128.4 |
| | (43.3 | ) | | 110.4 |
| Benefits paid | | (71.7 | ) | | (72.4 | ) | | (61.3 | ) | | (62.0 | ) | Fair value of plan assets, December 31 | | $ | 727.3 |
| | $ | 849.6 |
| | $ | 676.7 |
| | $ | 781.3 |
|
|
| Schedule of Allocation of Plan Assets [Table Text Block] |
The pension plan asset allocation at December 31, 2018 and 2017 and the target allocation for 2019 are as follows: | | | | | | | | | | | | | Percentage of Plan Assets | | | Target Allocation | |
December 31, | Asset Category | | 2019 | | 2018 | | 2017 | Equity Securities | | 58 | % | | 55 | % | | 58 | % | Fixed Income | | 33 | % | | 34 | % | | 31 | % | Hedge Funds | | 9 | % | | 11 | % | | 11 | % |
|
| Schedule of Fair Value of Plan, Assets by Measurement Levels [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of dollars | | 2018 | | 2017 | | 2018 | | 2017 | Investments with fair value measure at Level 2: | | | | | | | | | Mutual funds | | $ | 107 |
| | $ | 120 |
| | $ | 99 |
| | $ | 110 |
| Short-term investment vehicles | | 20 |
| | 17 |
| | 19 |
| | 16 |
| US Treasury securities | | 7 |
| | 15 |
| | 7 |
| | 14 |
| Corporate debt instruments | | 92 |
| | 91 |
| | 86 |
| | 84 |
| Government and other debt instruments | | 18 |
| | 17 |
| | 16 |
| | 15 |
| Total assets in the fair value hierarchy | | 244 |
| | 260 |
| | 227 |
| | 239 |
| | | | | | | | | | Investments at net asset value: | | | | | | | | | Common collective trust | | 400 |
| | 498 |
| | 373 |
| | 458 |
| Joint venture interests | | 83 |
| | 92 |
| | 77 |
| | 84 |
| Total investments at fair value | | $ | 727 |
| | $ | 850 |
| | $ | 677 |
| | $ | 781 |
|
|
| Schedule of Expected Benefit Payments [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | 2019 | | $ | 71.5 |
| | $ | 13.6 |
| | $ | 71.5 |
| | $ | 10.8 |
| 2020 | | 62.4 |
| | 14.3 |
| | 62.4 |
| | 11.4 |
| 2021 | | 65.6 |
| | 14.9 |
| | 65.6 |
| | 11.8 |
| 2022 | | 69.6 |
| | 15.4 |
| | 69.6 |
| | 12.2 |
| 2023 | | 66.6 |
| | 15.8 |
| | 66.6 |
| | 12.6 |
| 2024-2028 | | 284.9 |
| | 82.3 |
| | 284.9 |
| | 65.4 |
|
|
| Schedule of Net Benefit Costs [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Pension Benefits | | Other Postretirement Benefits | Millions of dollars | | 2018 | | 2017 | | 2016 | | 2018 | | 2017 | | 2016 | Service cost | | $ | 21.0 |
| | $ | 21.7 |
| | $ | 20.7 |
| | $ | 4.6 |
| | $ | 4.5 |
| | $ | 4.4 |
| Interest cost | | 34.1 |
| | 37.4 |
| | 39.4 |
| | 10.1 |
| | 11.5 |
| | 12.1 |
| Expected return on assets | | (56.7 | ) | | (54.7 | ) | | (55.9 | ) | | n/a |
| | n/a |
| | n/a |
| Prior service cost amortization | | 0.5 |
| | 1.6 |
| | 3.9 |
| | — |
| | — |
| | 0.3 |
| Amortization of actuarial losses | | 12.8 |
| | 16.3 |
| | 14.8 |
| | 0.7 |
| | 1.0 |
| | 0.5 |
| Net periodic benefit cost | | $ | 11.7 |
| | $ | 22.3 |
| | $ | 22.9 |
| | $ | 15.4 |
| | $ | 17.0 |
| | $ | 17.3 |
|
|
| Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] |
Amounts recognized in accumulated other comprehensive loss were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | December 31, | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Net actuarial loss | | $ | 12.8 |
| | $ | 8.8 |
| | $ | 1.1 |
| | $ | 3.5 |
| | $ | 3.4 |
| | $ | 2.1 |
| | $ | 0.5 |
| | $ | 1.5 |
| Prior service cost | | 0.1 |
| | 0.1 |
| | — |
| | — |
| | — |
| | — |
| | — |
| | — |
| Total | | $ | 12.9 |
| | $ | 8.9 |
| | $ | 1.1 |
| | $ | 3.5 |
| | $ | 3.4 |
| | $ | 2.1 |
| | $ | 0.5 |
| | $ | 1.5 |
|
|
| Schedule of defined benefit plan, Other changes in plan assets recognized in regulatory assets [Table Text Block] |
Other changes in plan assets and benefit obligations recognized in regulatory assets were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Pension Benefits | | Other Postretirement Benefits | Millions of dollars | | 2018 | | 2017 | | 2016 | | 2018 | | 2017 | | 2016 | Current year actuarial (gain) loss | | $ | 46.7 |
| | $ | (27.1 | ) | | $ | 29.4 |
| | $ | (31.8 | ) | | $ | 9.4 |
| | $ | 11.1 |
| Amortization of actuarial losses | | (11.1 | ) | | (14.1 | ) | | (12.7 | ) | | (0.6 | ) | | (0.8 | ) | | (0.4 | ) | Amortization of prior service cost | | (0.5 | ) | | (1.4 | ) | | (3.4 | ) | | — |
| | — |
| | (0.3 | ) | Total recognized in regulatory assets | | $ | 35.1 |
| | $ | (42.6 | ) | | $ | 13.3 |
| | $ | (32.4 | ) | | $ | 8.6 |
| | $ | 10.4 |
|
|
| Schedule of Assumptions Used in Determining Net Periodic Benefit Cost [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | Pension Benefits | | Other Postretirement Benefits | | 2018 | | 2017 | | 2016 | | 2018 | | 2017 | | 2016 | Discount rate | 3.71 | % | | 4.22 | % | | 4.68 | % | | 3.74 | % | | 4.30 | % | | 4.78 | % | Expected return on plan assets | 7.00 | % | | 7.25 | % | | 7.50 | % | | n/a |
| | n/a |
| | n/a |
| Rate of compensation increase | 3.00 | % | | 3.00 | % | | 3.00 | % | | 3.00 | % | | 3.00 | % | | 3.00 | % | Health care cost trend rate | n/a |
| | n/a |
| | n/a |
| | 7.00 | % | | 6.60 | % | | 7.00 | % | Ultimate health care cost trend rate | n/a |
| | n/a |
| | n/a |
| | 5.00 | % | | 5.00 | % | | 5.00 | % | Year achieved | n/a |
| | n/a |
| | n/a |
| | 2023 |
| | 2021 |
| | 2021 |
|
|
| Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year [Table Text Block] |
The estimated amounts to be amortized from accumulated other comprehensive loss into net periodic benefit cost in 2019 are as follows for the Company. For Consolidated SCE&G such amounts are insignificant: | | | | | | | | | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | Actuarial loss | | $ | 0.8 |
| | — |
|
|
| Schedule of amounts in regulatory assets to be recognized over the next fiscal year [Table Text Block] |
The estimated amounts to be amortized from regulatory assets into net periodic benefit cost in 2019 are as follows: | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | Actuarial loss | | $ | 14.7 |
| | — |
| | $ | 12.9 |
| | — |
| Prior service cost | | 0.3 |
| | — |
| | 0.3 |
| | — |
| Total | | $ | 15.0 |
| | — |
| | $ | 13.2 |
| | — |
|
|
| SCE&G |
|
| Defined Benefit Plan Disclosure [Line Items] |
|
| Schedule of Changes in Projected Benefit Obligations [Table Text Block] |
The measurement date used to determine pension and other postretirement benefit obligations is December 31. Data related to the changes in the projected benefit obligation for pension benefits and the accumulated benefit obligation for other postretirement benefits are presented below. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | | | Pension Benefits |
| Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | Millions of dollars | | 2018 |
| 2017 |
| 2018 |
| 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Benefit obligation, January 1 | | $ | 933.2 |
| | $ | 904.3 |
| | $ | 289.2 |
| | $ | 274.7 |
| | $ | 793.0 |
| | $ | 768.4 |
| | $ | 216.6 |
| | $ | 207.2 |
| Service cost | | 21.0 |
| | 21.7 |
| | 4.6 |
| | 4.5 |
| | 17.1 |
| | 18.1 |
| | 3.6 |
| | 3.7 |
| Interest cost | | 34.1 |
| | 37.4 |
| | 10.1 |
| | 11.5 |
| | 29.0 |
| | 31.9 |
| | 8.0 |
| | 9.5 |
| Plan participants’ contributions | | — |
| | — |
| | 1.4 |
| | 1.3 |
| | — |
| | — |
| | 1.1 |
| | 1.1 |
| Actuarial (gain) loss | | (53.1 | ) | | 42.2 |
| | (38.4 | ) | | 9.7 |
| | (45.5 | ) | | 36.6 |
| | (30.7 | ) | | 6.8 |
| Benefits paid | | (71.7 | ) | | (72.4 | ) | | (13.2 | ) | | (12.5 | ) | | (61.3 | ) | | (62.0 | ) | | (10.4 | ) | | (10.3 | ) | Amounts funded to parent | | n/a |
| | n/a |
| | n/a |
| | n/a |
| | — |
| | — |
| | (0.8 | ) | | (1.4 | ) | Benefit obligation, December 31 | | $ | 863.5 |
| | $ | 933.2 |
| | $ | 253.7 |
| | $ | 289.2 |
| | $ | 732.3 |
| | $ | 793.0 |
| | $ | 187.4 |
| | $ | 216.6 |
|
|
| Schedule of Assumptions Used to Determine Benefit Obligations [Table Text Block] |
Significant assumptions used to determine the above benefit obligations are as follows: | | | | | | | | | | | | | | Pension Benefits | | Other Postretirement Benefits | | 2018 | | 2017 | | 2018 | | 2017 | Annual discount rate used to determine benefit obligation | 4.35 | % | | 3.71 | % | | 4.38 | % | | 3.74 | % | Assumed annual rate of future salary increases for projected benefit obligation | 3.00 | % | | 3.00 | % | | 3.00 | % | | 3.00 | % |
|
| Schedule of Net Funded Status [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | December 31, | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Fair value of plan assets | | $ | 727.3 |
| | $ | 849.6 |
| | — |
| | — |
| | $ | 676.7 |
| | $ | 781.3 |
| | — |
| | — |
| Benefit obligation | | 863.5 |
| | 933.2 |
| | $ | 253.7 |
| | $ | 289.2 |
| | 732.3 |
| | 793.0 |
| | $ | 187.4 |
| | $ | 216.6 |
| Funded status | | $ | (136.2 | ) | | $ | (83.6 | ) | | $ | (253.7 | ) | | $ | (289.2 | ) | | $ | (55.6 | ) | | $ | (11.7 | ) | | $ | (187.4 | ) | | $ | (216.6 | ) |
|
| Schedule of Amounts Recognized in Balance Sheet [Table Text Block] |
Amounts recognized in accumulated other comprehensive loss were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | December 31, | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Net actuarial loss | | $ | 12.8 |
| | $ | 8.8 |
| | $ | 1.1 |
| | $ | 3.5 |
| | $ | 3.4 |
| | $ | 2.1 |
| | $ | 0.5 |
| | $ | 1.5 |
| Prior service cost | | 0.1 |
| | 0.1 |
| | — |
| | — |
| | — |
| | — |
| | — |
| | — |
| Total | | $ | 12.9 |
| | $ | 8.9 |
| | $ | 1.1 |
| | $ | 3.5 |
| | $ | 3.4 |
| | $ | 2.1 |
| | $ | 0.5 |
| | $ | 1.5 |
|
|
| Schedule of Defined Benefit Plan, Amounts Recognized in Accumulated Other Comprehensive Income (Loss) [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | | Consolidated SCE&G | | Pension Benefits | | Other Postretirement Benefits | Millions of dollars | | 2018 | | 2017 | | 2016 | | 2018 | | 2017 | | 2016 | Current year actuarial loss | | $ | 1.4 |
| | $ | 0.3 |
| | — |
| | $ | (1.0 | ) | | $ | 0.5 |
| | $ | 0.3 |
| Amortization of actuarial losses | | (0.1 | ) | | (0.1 | ) | | $ | (0.1 | ) | | — |
| | — |
| | — |
| Total recognized in OCI | | $ | 1.3 |
| | $ | 0.2 |
| | $ | (0.1 | ) | | $ | (1.0 | ) | | $ | 0.5 |
| | $ | 0.3 |
|
|
| Schedule of defined benefit plan, amounts recognized in regulatory assets [Table Text Block] |
Amounts recognized in regulatory assets were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | December 31, | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Net actuarial loss | | $ | 230.4 |
| | $ | 194.8 |
| | $ | 10.9 |
| | $ | 43.3 |
| | $ | 202.4 |
| | $ | 171.4 |
| | $ | 9.0 |
| | $ | 35.9 |
| Prior service cost | | 0.7 |
| | 1.2 |
| | — |
| | — |
| | 0.6 |
| | 1.0 |
| | — |
| | — |
| Total | | $ | 231.1 |
| | $ | 196.0 |
| | $ | 10.9 |
| | $ | 43.3 |
| | $ | 203.0 |
| | $ | 172.4 |
| | $ | 9.0 |
| | $ | 35.9 |
|
|
| Schedule of Changes in Fair Value of Plan Assets [Table Text Block] |
| | | | | | | | | | | | | | | | | | Pension Benefits
| | The Company | | Consolidated SCE&G | Millions of dollars | | 2018 | | 2017 | | 2018 | | 2017 | Fair value of plan assets, January 1 | | $ | 849.6 |
| | $ | 793.6 |
| | $ | 781.3 |
| | $ | 732.9 |
| Actual return (loss) on plan assets | | (50.6 | ) | | 128.4 |
| | (43.3 | ) | | 110.4 |
| Benefits paid | | (71.7 | ) | | (72.4 | ) | | (61.3 | ) | | (62.0 | ) | Fair value of plan assets, December 31 | | $ | 727.3 |
| | $ | 849.6 |
| | $ | 676.7 |
| | $ | 781.3 |
|
|
| Schedule of Allocation of Plan Assets [Table Text Block] |
The pension plan asset allocation at December 31, 2018 and 2017 and the target allocation for 2019 are as follows: | | | | | | | | | | | | | Percentage of Plan Assets | | | Target Allocation | |
December 31, | Asset Category | | 2019 | | 2018 | | 2017 | Equity Securities | | 58 | % | | 55 | % | | 58 | % | Fixed Income | | 33 | % | | 34 | % | | 31 | % | Hedge Funds | | 9 | % | | 11 | % | | 11 | % |
|
| Schedule of Fair Value of Plan, Assets by Measurement Levels [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of dollars | | 2018 | | 2017 | | 2018 | | 2017 | Investments with fair value measure at Level 2: | | | | | | | | | Mutual funds | | $ | 107 |
| | $ | 120 |
| | $ | 99 |
| | $ | 110 |
| Short-term investment vehicles | | 20 |
| | 17 |
| | 19 |
| | 16 |
| US Treasury securities | | 7 |
| | 15 |
| | 7 |
| | 14 |
| Corporate debt instruments | | 92 |
| | 91 |
| | 86 |
| | 84 |
| Government and other debt instruments | | 18 |
| | 17 |
| | 16 |
| | 15 |
| Total assets in the fair value hierarchy | | 244 |
| | 260 |
| | 227 |
| | 239 |
| | | | | | | | | | Investments at net asset value: | | | | | | | | | Common collective trust | | 400 |
| | 498 |
| | 373 |
| | 458 |
| Joint venture interests | | 83 |
| | 92 |
| | 77 |
| | 84 |
| Total investments at fair value | | $ | 727 |
| | $ | 850 |
| | $ | 677 |
| | $ | 781 |
|
|
| Schedule of Expected Benefit Payments [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | 2019 | | $ | 71.5 |
| | $ | 13.6 |
| | $ | 71.5 |
| | $ | 10.8 |
| 2020 | | 62.4 |
| | 14.3 |
| | 62.4 |
| | 11.4 |
| 2021 | | 65.6 |
| | 14.9 |
| | 65.6 |
| | 11.8 |
| 2022 | | 69.6 |
| | 15.4 |
| | 69.6 |
| | 12.2 |
| 2023 | | 66.6 |
| | 15.8 |
| | 66.6 |
| | 12.6 |
| 2024-2028 | | 284.9 |
| | 82.3 |
| | 284.9 |
| | 65.4 |
|
|
| Schedule of Net Benefit Costs [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | | Consolidated SCE&G | | Pension Benefits | | Other Postretirement Benefits | Millions of dollars | | 2018 | | 2017 | | 2016 | | 2018 | | 2017 | | 2016 | Service cost | | $ | 17.1 |
| | $ | 18.1 |
| | $ | 16.9 |
| | $ | 3.6 |
| | $ | 3.7 |
| | $ | 3.6 |
| Interest cost | | 29.0 |
| | 31.9 |
| | 33.4 |
| | 8.0 |
| | 9.5 |
| | 9.9 |
| Expected return on assets | | (48.1 | ) | | (46.7 | ) | | (47.4 | ) | | n/a |
| | n/a |
| | n/a |
| Prior service cost amortization | | 0.4 |
| | 1.4 |
| | 3.4 |
| | — |
| | — |
| | 0.3 |
| Amortization of actuarial losses | | 10.9 |
| | 13.9 |
| | 12.5 |
| | 0.6 |
| | 0.8 |
| | 0.4 |
| Net periodic benefit cost | | $ | 9.3 |
| | $ | 18.6 |
| | $ | 18.8 |
| | $ | 12.2 |
| | $ | 14.0 |
| | $ | 14.2 |
|
|
| Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] |
Amounts recognized in accumulated other comprehensive loss were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | December 31, | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | | 2018 | | 2017 | Net actuarial loss | | $ | 12.8 |
| | $ | 8.8 |
| | $ | 1.1 |
| | $ | 3.5 |
| | $ | 3.4 |
| | $ | 2.1 |
| | $ | 0.5 |
| | $ | 1.5 |
| Prior service cost | | 0.1 |
| | 0.1 |
| | — |
| | — |
| | — |
| | — |
| | — |
| | — |
| Total | | $ | 12.9 |
| | $ | 8.9 |
| | $ | 1.1 |
| | $ | 3.5 |
| | $ | 3.4 |
| | $ | 2.1 |
| | $ | 0.5 |
| | $ | 1.5 |
|
|
| Schedule of defined benefit plan, Other changes in plan assets recognized in regulatory assets [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | | Consolidated SCE&G | | Pension Benefits | | Other Postretirement Benefits | Millions of dollars | | 2018 | | 2017 | | 2016 | | 2018 | | 2017 | | 2016 | Current year actuarial (gain) loss | | $ | 40.7 |
| | $ | (24.8 | ) | | $ | 26.3 |
| | $ | (26.4 | ) | | $ | 7.3 |
| | $ | 9.2 |
| Amortization of actuarial losses | | (9.7 | ) | | (12.5 | ) | | (11.2 | ) | | (0.5 | ) | | (0.7 | ) | | (0.3 | ) | Amortization of prior service cost | | (0.4 | ) | | (1.3 | ) | | (3.0 | ) | | — |
| | — |
| | (0.2 | ) | Total recognized in regulatory assets | | $ | 30.6 |
| | $ | (38.6 | ) | | $ | 12.1 |
| | $ | (26.9 | ) | | $ | 6.6 |
| | $ | 8.7 |
|
|
| Schedule of Assumptions Used in Determining Net Periodic Benefit Cost [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | Pension Benefits | | Other Postretirement Benefits | | 2018 | | 2017 | | 2016 | | 2018 | | 2017 | | 2016 | Discount rate | 3.71 | % | | 4.22 | % | | 4.68 | % | | 3.74 | % | | 4.30 | % | | 4.78 | % | Expected return on plan assets | 7.00 | % | | 7.25 | % | | 7.50 | % | | n/a |
| | n/a |
| | n/a |
| Rate of compensation increase | 3.00 | % | | 3.00 | % | | 3.00 | % | | 3.00 | % | | 3.00 | % | | 3.00 | % | Health care cost trend rate | n/a |
| | n/a |
| | n/a |
| | 7.00 | % | | 6.60 | % | | 7.00 | % | Ultimate health care cost trend rate | n/a |
| | n/a |
| | n/a |
| | 5.00 | % | | 5.00 | % | | 5.00 | % | Year achieved | n/a |
| | n/a |
| | n/a |
| | 2023 |
| | 2021 |
| | 2021 |
|
|
| Schedule of amounts in regulatory assets to be recognized over the next fiscal year [Table Text Block] |
The estimated amounts to be amortized from regulatory assets into net periodic benefit cost in 2019 are as follows: | | | | | | | | | | | | | | | | | | The Company | | Consolidated SCE&G | Millions of Dollars | | Pension Benefits | | Other Postretirement Benefits | | Pension Benefits | | Other Postretirement Benefits | Actuarial loss | | $ | 14.7 |
| | — |
| | $ | 12.9 |
| | — |
| Prior service cost | | 0.3 |
| | — |
| | 0.3 |
| | — |
| Total | | $ | 15.0 |
| | — |
| | $ | 13.2 |
| | — |
|
|