Palo Verde Sale Leaseback Variable Interest Entities (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Palo Verde Sale Leaseback Variable Interest Entities
Increase in net income due to consolidation of Palo Verde Sale Leaseback Trusts	$ 8,040,000	$ 7,426,000	$ 23,582,000	$ 20,041,000
Amounts relating to the VIEs included in Condensed Consolidated Balance Sheets
Palo Verde sale leaseback property plant and equipment, net of accumulated depreciation	129,962,000		129,962,000		132,864,000
Current maturities of long-term debt	90,360,000		90,360,000		477,435,000
Palo Verde sale leaseback lessor notes long-term debt excluding current maturities	57,420,000		57,420,000		65,547,000
Equity-Noncontrolling interests	129,342,000		129,342,000		108,736,000
ARIZONA PUBLIC SERVICE COMPANY
Palo Verde Sale Leaseback Variable Interest Entities
Number of VIE lessor trusts	3		3
Annual lease payments			49,000,000
Increase in net income due to consolidation of Palo Verde Sale Leaseback Trusts	8,040,000	7,435,000	23,573,000	20,089,000
Amounts relating to the VIEs included in Condensed Consolidated Balance Sheets
Palo Verde sale leaseback property plant and equipment, net of accumulated depreciation	129,962,000		129,962,000		132,864,000
Current maturities of long-term debt	90,360,000		90,360,000		477,435,000
Palo Verde sale leaseback lessor notes long-term debt excluding current maturities	57,420,000		57,420,000		65,547,000
Equity-Noncontrolling interests	129,342,000		129,342,000		108,399,000
ARIZONA PUBLIC SERVICE COMPANY | Consolidation of VIEs
Palo Verde Sale Leaseback Variable Interest Entities
Increase in net income due to consolidation of Palo Verde Sale Leaseback Trusts	8,000,000		24,000,000
Amounts relating to the VIEs included in Condensed Consolidated Balance Sheets
Palo Verde sale leaseback property plant and equipment, net of accumulated depreciation	130,000,000		130,000,000		133,000,000
Current maturities of long-term debt	26,000,000		26,000,000		31,000,000
Palo Verde sale leaseback lessor notes long-term debt excluding current maturities	57,000,000		57,000,000		66,000,000
Equity-Noncontrolling interests	129,000,000		129,000,000		108,000,000
Maximum payment to the VIEs' noncontrolling equity participants upon the occurrence of certain unlikely events			142,000,000
VIE debt to be assumed upon the occurrence of certain unlikely events			$ 83,000,000