Common Equity - Dividend Restrictions (Details)	9 Months Ended
	Sep. 30, 2015
PGL
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio required to be maintained (as a percent)	65.00%
WPS
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio required to be maintained (as a percent)	65.00%
WPS | Maximum [Member] | Public Service Commission of Wisconsin [Member]
Dividend Payment Restrictions [Line Items]
Percentage of previous period's dividend as restriction on current period dividends	103.00%
WPS | Minimum [Member]
Dividend Payment Restrictions [Line Items]
Percentage of common stockholders' equity to total capitalization required to be maintained	25.00%
WPS | Minimum [Member] | Public Service Commission of Wisconsin [Member]
Dividend Payment Restrictions [Line Items]
Common equity ratio required to be maintained (as a percent)	51.00%
Integrys
Dividend Payment Restrictions [Line Items]
Maximum debt to capitalization ratio required to be maintained (as a percent)	65.00%