Regulation and Rates (Details) (USD $) In Millions, unless otherwise specified													12 Months Ended
	Jul. 02, 2013 Subsidiaries [Member]	Jan. 02, 2014 Decoupling Mechanism [Member] Electric [Member]	Jan. 02, 2014 Decoupling Mechanism [Member] Natural Gas [Member]	May 01, 2014 Decoupling Mechanism [Member] Subsidiaries [Member] Electric [Member]	Jul. 02, 2013 Decoupling Mechanism [Member] Subsidiaries [Member] Electric [Member]	May 01, 2014 Decoupling Mechanism [Member] Subsidiaries [Member] Natural Gas [Member]	Jul. 02, 2013 Decoupling Mechanism [Member] Subsidiaries [Member] Natural Gas [Member]	Jul. 02, 2013 Expedited Rate Filing [Member] Subsidiaries [Member] Electric [Member]	Jul. 02, 2013 Expedited Rate Filing [Member] Subsidiaries [Member] Natural Gas [Member]	May 23, 2014 Power Cost Only Rate Case (PCORC) [Member] Subsidiaries [Member] Electric [Member]	Nov. 01, 2013 Power Cost Only Rate Case (PCORC) [Member] Subsidiaries [Member] Electric [Member]	Nov. 01, 2013 Purchased Gas Adjustment (PGA) [Member] Subsidiaries [Member] Natural Gas [Member]	Dec. 31, 2014 Scenario, Forecast [Member] Subsidiaries [Member]	May 01, 2014 Property tax tracker [Member] [Domain] [Domain] Subsidiaries [Member] Electric [Member]	May 01, 2014 Property tax tracker [Member] [Domain] [Domain] Subsidiaries [Member] Natural Gas [Member]	May 01, 2014 Conservation Rider [Member] Subsidiaries [Member] Electric [Member]	May 01, 2014 Conservation Rider [Member] Subsidiaries [Member] Natural Gas [Member]	Dec. 01, 2014 Subsequent Event [Member] Power Cost Only Rate Case (PCORC) [Member] Subsidiaries [Member] Electric [Member]	Nov. 01, 2014 Subsequent Event [Member] Purchased Gas Adjustment (PGA) [Member] Subsidiaries [Member] Natural Gas [Member]
Regulatory Assets [Line Items]
American Recovery and Reinvestment Tax Act of 2009, Grant Pass Through Amount													$ 37.8
American Recovery and Reinvestment Tax Act of 2009, Grant Pass Through Interest Amount													20.6
American Recovery and Reinvestment Tax Act of 2009, Grant, Overall Average Rate Reduction													(0.26%)
American Recovery and Reinvestment Tax Act of 2009, Total Grant Pass Through Amount													58.5
Public Utilities, Rate Case, Approved Effective Annual Rate Increase (Decrease)				$ 10.6	$ 21.4	$ 1.0	$ 10.8	$ 30.7	$ (2.0)	$ 9.6	$ (10.5)	$ 4.0		$ 11.0	$ 5.6	$ 12.2	$ 0.3	$ 14.9	$ 19.9
Public Utilities, Rate Case, Approved Effective Annual Rate Percentage Increase (Decrease)		3.00%	2.20%	0.50%	1.00%	0.10%	1.10%	1.50%	(0.20%)	0.50%	(0.50%)	0.40%			0.60%	0.50%		0.00%
Rate Case, Approved Effective Weighted Cost of Capital	7.77%
Rate Case, Approved Effective Common Equity in Capital Structure	48.00%
Rate Case, Approved Effective Return on Equity	9.80%