XML 76 R65.htm IDEA: XBRL DOCUMENT v3.5.0.2
Other Commitments And Contingencies (Narrative) (Details)
$ in Millions
 9 Months Ended
Apr. 17, 2015
USD ($)
Sep. 30, 2016
USD ($)
Dec. 31, 2015
USD ($)
Other Commitments And Contingencies [Line Items]      
Proposed Pipeline Safety Rule, time period for investigation and repair/replace activity on facilities   15 years  
Recorded reserves to cover environmental remediation at various sites   $ 116.9 $ 123.2
Number of countries agreeing to limit GHGs   194  
Proposed reduction in GHG levels   26-28%  
Estimated Cost of Compliance with Effluent Limitations Guidelines   $ 170.0  
Estimated Cost of Compliance with Coal Combustion Residuals $ 230.0    
Transmission Upgrade Agreement Multiplier   1.71  
MGP Sites      
Other Commitments And Contingencies [Line Items]      
Number of waste disposal sites identified by program   64  
Liability for Estimated Remediation Costs   $ 108.3 $ 110.4
Reasonably possible remediation costs variance from reserve   25.0  
NIPSCO      
Other Commitments And Contingencies [Line Items]      
Upgrade Sponsors Liability related to Portion Collected for Taxes on TUA   8.6  
Gain (Loss) on Contract Termination   16.0  
Letters Of Credit      
Other Commitments And Contingencies [Line Items]      
Guarantor Obligations, Maximum Exposure, Undiscounted   $ 14.7  
Maximum      
Other Commitments And Contingencies [Line Items]      
Ozone Level   75 ppb  
Estimated Cost of Compliance with Clean Water Act, minimum   $ 35.0  
Maximum | NIPSCO      
Other Commitments And Contingencies [Line Items]      
Severance Costs   15.0  
Total Severance and Contract Termination Cost   $ 31.0  
Minimum      
Other Commitments And Contingencies [Line Items]      
Ozone Level   70 ppb  
Estimated Cost of Compliance with Clean Water Act, minimum   $ 0.0  
Minimum | NIPSCO      
Other Commitments And Contingencies [Line Items]      
Cost to Maintain and Operate Current Fleet of Coal-Fired Generating Units   1,000.0  
Severance Costs   10.0  
Total Severance and Contract Termination Cost   $ 26.0