Commitments and Contingencies (Details 2) (ARIZONA PUBLIC SERVICE COMPANY, USD $) In Millions, unless otherwise specified	0 Months Ended	1 Months Ended	6 Months Ended						0 Months Ended
	Jan. 22, 2014 item	Sep. 30, 2011 item MW kV	Jun. 30, 2014	Jun. 30, 2014 Letters of credit expiring in 2015 item	Jun. 30, 2014 Letters of credit expiring in 2016 item	Jun. 30, 2014 Variable interest rate pollution control bonds	Jun. 30, 2014 Equity Lessors in Palo Verde sale leaseback transactions	Jun. 30, 2014 Natural gas tolling contract obligations	Jul. 07, 2014 Subsequent event item	Aug. 06, 2013 Contaminated groundwater wells item
Superfund-Related Matters
Costs related to investigation and study under Superfund site			$ 2
Number of defendants against whom Roosevelt Irrigation District ("RID") filed lawsuit										24
Southwest Power Outage
Capacity of transmission line that tripped out of service (in kV)		500
Period, after the transmission line went off-line, over which generation and transmission resources for the Yuma area were lost		10 minutes
Number of customers losing service in Yuma area		69,700
Capacity of firm load that were reported to have been affected due to outages affecting portions of southern Arizona, southern California and northern Mexico (in MW)		7,900
Number of customers that were reported to have been affected due to outages		2,700,000
Number of alleged entities	6
Number of Reliability Standard Requirements Violations alleged	7
Number of Reliability Standard Requirements neither admitted nor denied violations in settlement									4
Amount of civil penalty agreed in settlement									3.25
Civil penalty amount required to be paid in equal parts									2
Civil penalty amount offset in exchange for completing certain reliability enhancements									1.25
Financial Assurances
Outstanding letters of credit						$ 76	$ 24	$ 5
Number of letters of credit expiring				1	2