ÐÇ¿Õ´«Ã½

Annual report pursuant to Section 13 and 15(d)

PENSIONS AND OTHER POSTRETIREMENT BENEFITS - VEBA (Fair Values of Other Benefit Plan Assets) (Details)

v3.19.3.a.u2
PENSIONS AND OTHER POSTRETIREMENT BENEFITS - VEBA (Fair Values of Other Benefit Plan Assets) (Details) - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Significant Unobservable Inputs (Level 3) [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount $ 212.4 $ 229.1 $ 215.6
Significant Unobservable Inputs (Level 3) [Member] | Hedge Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 40.2 37.2 37.4
Significant Unobservable Inputs (Level 3) [Member] | Private Equity Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 49.5 42.6 39.8
Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 70.4 70.5 65.5
Other Postretirement Benefits Plan [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 259.7 240.2 262.5
Other Postretirement Benefits Plan [Member] | U.S. large-cap Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 9.3 9.7 Ìý
Other Postretirement Benefits Plan [Member] | U.S. small/mid-cap Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 2.3 2.4 Ìý
Other Postretirement Benefits Plan [Member] | International Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 7.0 7.3 Ìý
Other Postretirement Benefits Plan [Member] | Fixed Income Investments [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 207.3 184.6 Ìý
Other Postretirement Benefits Plan [Member] | Hedge Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 12.4 11.4 Ìý
Other Postretirement Benefits Plan [Member] | Private Equity Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 1.7 3.0 Ìý
Other Postretirement Benefits Plan [Member] | Structured Credit [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 5.5 8.5 Ìý
Other Postretirement Benefits Plan [Member] | Real Estate [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 14.0 13.1 Ìý
Other Postretirement Benefits Plan [Member] | Cash [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.2 0.2 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 185.2 166.4 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | U.S. large-cap Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 9.3 9.7 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | U.S. small/mid-cap Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 2.3 2.4 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | International Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 7.0 7.3 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fixed Income Investments [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 166.4 146.8 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Hedge Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Private Equity Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Structured Credit [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Real Estate [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Cash [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.2 0.2 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 40.9 37.8 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | U.S. large-cap Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | U.S. small/mid-cap Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | International Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | Fixed Income Investments [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 40.9 37.8 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | Hedge Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | Private Equity Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | Structured Credit [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | Real Estate [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Other Observable Inputs (Level 2) | Cash [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 33.6 36.0 35.2
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. large-cap Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. small/mid-cap Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | International Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fixed Income Investments [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 Ìý
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | Hedge Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 12.4 11.4 11.4
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | Private Equity Funds [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 1.7 3.0 3.9
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | Structured Credit [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 5.5 8.5 7.9
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | Real Estate [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount 14.0 13.1 $ 12.0
Other Postretirement Benefits Plan [Member] | Significant Unobservable Inputs (Level 3) [Member] | Cash [Member] Ìý Ìý Ìý
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Ìý Ìý Ìý
Defined Benefit Plan, Plan Assets, Amount $ 0.0 $ 0.0 Ìý