XML 29 R15.htm IDEA: XBRL DOCUMENT
v3.23.2

Property, Plant, Equipment and Mine Development | 6 Months Ended
--- | ---
Jun. 30, 2023
Property, Plant and Equipment [Abstract] |
Property, Plant, Equipment and Mine Development | Property, Plant, Equipment and Mine Development The composition of property, plant, equipment and mine development, net, as of June 30, 2023 and December 31, 2022 is set forth in the table below:
| June 30, 2023 |  | December 31, 2022
| (Dollars in millions)
Land and coal interests | $ | 2,511.9 |  |  | $ | 2,514.7 |
Buildings and improvements | 628.8 |  |  | 594.2 |
Machinery and equipment | 1,612.0 |  |  | 1,543.1 |
Less: Accumulated depreciation, depletion and amortization | (1,933.2) |  |  | (1,787.0) |
Property, plant, equipment and mine development, net | $ | 2,819.5 |  |  | $ | 2,865.0 |

X
- References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for long-lived, physical asset used in normal conduct of business and not intended for resale. Includes, but is not limited to, work of art, historical treasure, and similar asset classified as collections. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org//360/tableOfContent Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 6 -SubTopic 360 -Topic 958 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480321/958-360-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -SubTopic 360 -Topic 958 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480321/958-360-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 7 -SubTopic 360 -Topic 958 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480321/958-360-50-7 + Details
Name: | us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration