Common Equity - Dividend Restrictions (Details) $ in Billions	12 Months Ended
	Dec. 31, 2016 USD ($) period	Dec. 31, 2015
Dividend Payment Restrictions [Line Items]
Junior notes minimum interest deferral payment period (in periods) | period	1
Junior notes maximum interest payment deferral period (in years)	10 years
Restricted net assets of subsidiaries and undistributed earnings of equity method investments | $	$ 6.3
Percentage of restricted net assets of subsidiaries and equity method investments that triggers dividend restriction disclosures	25.00%
WE | Serial preferred stock, 3.60% series redeemable
Dividend Payment Restrictions [Line Items]
Preferred Stock, dividend rate (as a percent)	3.60%	3.60%
WE | Serial preferred stock, 3.60% series redeemable | Common stock equity to total capitalization is less than 25%
Dividend Payment Restrictions [Line Items]
Percentage of net income for which dividends can be declared	75.00%
WE | Serial preferred stock, 3.60% series redeemable | Common stock equity to total capitalization is less than 20%
Dividend Payment Restrictions [Line Items]
Percentage of net income for which dividends can be declared	50.00%
WE | Minimum | Public Service Commission of Wisconsin
Dividend Payment Restrictions [Line Items]
Common equity ratio required to be maintained (as a percent)	51.00%
WE | Maximum | Serial preferred stock, 3.60% series redeemable | Common stock equity to total capitalization is less than 25%
Dividend Payment Restrictions [Line Items]
Percentage of common equity to total capitalization required to be maintained	25.00%
WE | Maximum | Serial preferred stock, 3.60% series redeemable | Common stock equity to total capitalization is less than 20%
Dividend Payment Restrictions [Line Items]
Percentage of common equity to total capitalization required to be maintained	20.00%
WG | Minimum | Public Service Commission of Wisconsin
Dividend Payment Restrictions [Line Items]
Common equity ratio required to be maintained (as a percent)	49.50%
WPS | Minimum | Public Service Commission of Wisconsin
Dividend Payment Restrictions [Line Items]
Common equity ratio required to be maintained (as a percent)	51.00%