Long Term Debt (Details) (USD $) In Millions, unless otherwise specified		9 Months Ended			9 Months Ended
	Sep. 30, 2014 Wis Elec Debenture due June 1, 2044 [Member]	Sep. 30, 2014 Wis Elec Debentures due April 1, 2014 [Member]	Sep. 30, 2013 Wisc Gas Debentures Due Sept 15 2013 [Domain]	Sep. 30, 2013 Wis Elec Debenture due June, 15 2018 [Domain]	Sep. 30, 2013 Wis Elec Debentures due May 15 2013 [Domain]
Long Term Debt (Textuals)
Issuance of long-term debt	$ 250			$ 250
Interest rate on long-term debt	4.25%			1.70%
Retirement of long-term debt		$ 300	$ 45		$ 300