XML 56 R43.htm IDEA: XBRL DOCUMENT
v3.8.0.1

COMMITMENTS AND CONTINGENCIES (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract] |
Schedule of regulatory assets and reserves related to manufactured gas plant sites | We have established the following regulatory assets and reserves related to manufactured gas plant sites:
(in millions) |  | March 31, 2018 |  | December 31, 2017
Regulatory assets |  | $ | 668.2 |  |  | $ | 676.6 |
Reserves for future remediation |  | 617.2 |  |  | 617.2 |

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

X
- Definition Tabular disclosure of information about obligations resulting from other commitments. + References No definition available. + Details
Name: | us-gaap_OtherCommitmentsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration