Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Preferred Stock, Value, Issued	$ 30.4	$ 30.4
WEC Energy Group | $.01 pare value preferred stock
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	15,000,000	15,000,000
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Value, Issued	$ 0.0	$ 0.0
WE | Six per cent. preferred stock
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 100	$ 100
Preferred Stock, Dividend Rate, Percentage	6.00%	6.00%
Preferred Stock, Shares Authorized	45,000	45,000
Preferred Stock, Shares Outstanding	44,498	44,498
Preferred Stock, Redemption Price Per Share	$ 0	$ 0
Preferred Stock, Value, Issued	$ 4.4	$ 4.4
WE | Serial preferred stock, $100 par value; authorized 2,286,500 shares
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 100	$ 100
Preferred Stock, Shares Authorized	2,286,500	2,286,500
WE | Serial preferred stock, 3.60% series redeemable
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 100	$ 100
Preferred Stock, Dividend Rate, Percentage	3.60%	3.60%
Preferred Stock, Shares Outstanding	260,000	260,000
Preferred Stock, Redemption Price Per Share	$ 101	$ 101
Preferred Stock, Value, Issued	$ 26.0	$ 26.0
WE | Serial preferred stock, $25 par value; authorized 5,000,000 shares; none outstanding
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 25	$ 25
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Value, Issued	$ 0.0	$ 0.0
WPS | $100 par value, preferred stock WPS
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 100	$ 100
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Value, Issued	$ 0.0	$ 0.0
PGL | $100 par value, cumulative preferred stock PGL
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 100	$ 100
Preferred Stock, Shares Authorized	430,000	430,000
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Value, Issued	$ 0.0	$ 0.0
NSG | $100 par value, cumulative preferred stock NSG
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 100	$ 100
Preferred Stock, Shares Authorized	160,000	160,000
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Value, Issued	$ 0.0	$ 0.0