Preferred Stock (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]
Preferred Stock, Value, Issued	$ 30.4	$ 30.4
Six Per Cent. Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	45,000
Preferred Stock, Shares Outstanding	44,498
Preferred Stock, Redemption Price Per Share	$ 0
Preferred Stock, Value, Issued	4.4
Serial preferred stock, $100 par value; authorized 2,286,500 shares [Member] [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	2,286,500
Serial preferred stock, 3.60% Series Redeemable [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	260,000
Preferred Stock, Redemption Price Per Share	$ 101
Preferred Stock, Value, Issued	26.0
Serial preferred stock, $25 par value; authorized 5,000,000 shares; none outstanding [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	5,000,000
Preferred Stock, Shares Outstanding	0
Preferred Stock, Redemption Price Per Share	$ 0
Preferred Stock, Value, Issued	0
Wisconsin Electric [Member]
Class of Stock [Line Items]
Preferred Stock, Value, Issued	30.4	30.4
Wisconsin Electric [Member] | Six Per Cent. Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized		45,000
Preferred Stock, Dividend Rate, Percentage	6.00%	6.00%
Preferred Stock, Par or Stated Value Per Share	$ 100.00	$ 100.00
Preferred Stock, Shares Outstanding		44,498
Preferred Stock, Redemption Price Per Share		$ 0
Preferred Stock, Value, Issued		4.4
Wisconsin Electric [Member] | Serial preferred stock, $100 par value; authorized 2,286,500 shares [Member] [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized		2,286,500
Preferred Stock, Par or Stated Value Per Share	$ 100.00	$ 100.00
Wisconsin Electric [Member] | Serial preferred stock, 3.60% Series Redeemable [Member]
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage	3.60%	3.60%
Preferred Stock, Par or Stated Value Per Share	$ 100.00	$ 100.00
Preferred Stock, Shares Outstanding		260,000
Preferred Stock, Redemption Price Per Share		$ 101
Preferred Stock, Value, Issued		26.0
Wisconsin Electric [Member] | Serial preferred stock, $25 par value; authorized 5,000,000 shares; none outstanding [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized		5,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0	$ 0
Preferred Stock, Shares Outstanding		0
Preferred Stock, Redemption Price Per Share		$ 0
Preferred Stock, Value, Issued		0
Wisconsin Energy Corporation [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	15,000,000	15,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Redemption Price Per Share	$ 0	$ 0
Preferred Stock, Value, Issued	$ 0	$ 0