v2.4.0.8
Long Term Debt (Details) (USD $)
In Millions, unless otherwise specified
9 Months Ended
Sep. 30, 2013
Wisc Gas Debentures Due Sept 15 2013 [Domain]
 
Long Term Debt (Textuals)  
Retirement of long-term debt $ 45
Wis Elec Debenture due June, 15 2018 [Domain]
 
Long Term Debt (Textuals)  
Issuance of long-term debt 250
Interest rate on long-term debt 1.70%
Wis Elec Debentures due May 15 2013 [Domain]
 
Long Term Debt (Textuals)  
Retirement of long-term debt $ 300