Commitments and Contingencies - Palo Verde Nuclear Generating Station and Contractual Obligations (Details) (USD $)	0 Months Ended	12 Months Ended			0 Months Ended
	Jul. 07, 2014	Dec. 31, 2014 Trust	Dec. 31, 2013	Dec. 31, 2012	Aug. 18, 2014	Dec. 31, 1986 Trust
ARIZONA PUBLIC SERVICE COMPANY
Palo Verde Nuclear Generating Station [Abstract]
Litigation settlement, amount	$ 3,250,000
Maximum insurance against public liability per occurrence for a nuclear incident		13,600,000,000
Maximum available nuclear liability insurance		375,000,000
Remaining nuclear liability insurance through mandatory industry wide retrospective assessment program		13,200,000,000
Maximum assessment per reactor for each nuclear incident		127,300,000
Annual limit per incident with respect to maximum assessment		19,000,000
Number of VIE lessor trusts		3				3
Maximum potential retrospective assessment per incident of APS		111,000,000
Annual payment limitation with respect to maximum potential retrospective assessment		16,500,000
Amount of "all risk" (including nuclear hazards) insurance for property damage to, and decontamination of, property at Palo Verde		2,750,000,000
Maximum amount that APS could incur under the current NEIL policies for each retrospective assessment		20,000,000
Collateral assurance provided based on rating triggers		53,000,000
Period to provide collateral assurance based on rating triggers		20 days
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract]
2015		723,000,000
2016		747,000,000
2017		630,000,000
2018		610,000,000
2019		583,000,000
Thereafter		8,200,000,000
ARIZONA PUBLIC SERVICE COMPANY | Coal take-or-pay commitments
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract]
2015		151,000,000
2016		171,000,000
2017		195,000,000
2018		190,000,000
2019		194,000,000
Thereafter		2,469,000,000
Total obligation		3,400,000,000
Present value of commitments		2,200,000,000
Total purchases		237,000,000	188,000,000	196,000,000
ARIZONA PUBLIC SERVICE COMPANY | Renewable energy credits
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract]
2015		46,000,000
2016		42,000,000
2017		42,000,000
2018		42,000,000
2019		42,000,000
Thereafter		448,000,000
ARIZONA PUBLIC SERVICE COMPANY | Coal Mine Reclamation Obligations
Fuel and Purchased Power Commitments and Purchase Obligations [Abstract]
2015		1,000,000
2016		15,000,000
2017		17,000,000
2018		18,000,000
2019		19,000,000
Thereafter		281,000,000
Total obligation		198,000,000	207,000,000
Breach of Contract for Disposal of Spent Nuclear Fuel and/or High Level Radioactive Waste
Palo Verde Nuclear Generating Station [Abstract]
Litigation settlement, amount					57,400,000
Breach of Contract for Disposal of Spent Nuclear Fuel and/or High Level Radioactive Waste | ARIZONA PUBLIC SERVICE COMPANY
Palo Verde Nuclear Generating Station [Abstract]
Litigation settlement, amount					$ 16,700,000