Regulatory Matters (Details 2) (Four Corners, SCE, USD $) In Millions, unless otherwise specified		0 Months Ended
	Dec. 31, 2013	Dec. 30, 2013 APS MW
Acquisition
Total Entitlement		970
Ownership interest acquired		48.00%
Percent Owned		63.00%
Purchase price		$ 182
Plant-in-service		316
Acquisition adjustment		255
Decommissioning obligations		34
Mine reclamation obligations		93
Other various liabilities		18
Construction work in progress		11
Deferral balance related to the acquisition of SCE's interest in Units 4 and 5 and the closure of Four Corners Units 1-3	37
Capacity rights over the Arizona Transmission System assign to third-parties		1,555
Capacity rights related to marketing and trading group for transmission of the additional power received assign to third-parties		300
Net receipt due to negotiation of alternate arrangement		$ 40