Supplemental Financial Statement Information - Other Non-operating Income (Expense) (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |||||
|---|---|---|---|---|---|---|---|
Jun. 30, 2020 |
Dec. 31, 2019 |
Sep. 30, 2019 |
Jun. 30, 2019 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Disaggregation of Revenue [Line Items] | |||||||
| Rent, royalty income and other income | $ 0.9 | $ 2.9 | $ 3.1 | ||||
| Gains from disposal of property, plant and equipment, net | 2.9 | 90.7 | 1.3 | ||||
| Income (loss) from equity method investments | (7.0) | (10.7) | (1.0) | ||||
| Loss on sale of businesses, net | 0.0 | (1.9) | 0.0 | ||||
| Gain on joint venture deconsolidation | 0.0 | 0.0 | 15.9 | ||||
| Non-cash joint venture impairment charge | $ (2.4) | $ (11.4) | (2.4) | (11.4) | 0.0 | ||
| Revisions of estimates | 0.2 | 0.0 | |||||
| Other | 0.1 | 0.1 | 1.2 | ||||
| Other income, net | (1.2) | 69.7 | 20.5 | ||||
| Gain from sale of certain oil and gas rights | $ 62.4 | $ 29.3 | 91.7 | ||||
| Gain on asset sales, net | 2.5 | 89.8 | 0.0 | ||||
| Buyer of Formerly-Owned Business | |||||||
| Disaggregation of Revenue [Line Items] | |||||||
| Revisions of estimates | $ 4.3 | $ 0.0 | $ 0.0 | ||||
| X | ||||||||||
- Definition Other Asset Impairment Charges And Due From Affiliates, Allowance For Credit Loss No definition available.
|
| X | ||||||||||
- Definition Other Other Nonoperating Income (Expense) No definition available.
|
| X | ||||||||||
- Definition Rent, Royalty, And Other Income No definition available.
|
| X | ||||||||||
- Definition Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of gain (loss) from deconsolidation of subsidiary and derecognition of group of assets constituting transfer of business or nonprofit activity, excluding conveyance of oil and gas mineral rights and transfer of good or service in contract with customer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of gain (loss) on sale or disposal of oil and gas property or timber property. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of gain (loss) from the difference between the sale price or salvage price and the book value of an asset that was sold or retired, and gain (loss) from the write down of assets from their carrying value to fair value. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of income (loss) for proportionate share of equity method investee's income (loss). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of income (expense) related to nonoperating activities, classified as other. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|