Long Term Debt (Details) (USD $) In Millions, unless otherwise specified		6 Months Ended		6 Months Ended
	Jun. 30, 2014 Wis Elec Debenture due June 1, 2044 [Member]	Jun. 30, 2014 Wis Elec Debentures due April 1, 2014 [Member]	Jun. 30, 2013 Wis Elec Debenture due June, 15 2018 [Domain]	Jun. 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		$ 300