Long-Term Debt and Liquidity Matters - Components of Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Long-Term Debt and Liquidity Matters [Line Items]
Long-term debt	$ 3,415,000us-gaap_DebtAndCapitalLeaseObligations	$ 3,337,000us-gaap_DebtAndCapitalLeaseObligations
Long-term debt less current maturities	3,031,215us-gaap_LongTermDebtNoncurrent	2,796,465us-gaap_LongTermDebtNoncurrent
APS
Long-Term Debt and Liquidity Matters [Line Items]
Gross long-term debt	3,294,000
Unamortized discount	(9,206)	(8,732)
Unamortized premium	4,866	5,047
Long-term debt	3,289,785	3,211,889
Less current maturities	(383,570)	(540,424)
Total long-term debt less current maturities	2,906,215	2,671,465
Pinnacle West
Long-Term Debt and Liquidity Matters [Line Items]
Gross long-term debt	3,419,000
Long-term debt	125,000	125,000
Long-term debt less current maturities	125,000	125,000
Pollution Control Bonds - Variable \| APS
Long-Term Debt and Liquidity Matters [Line Items]
Gross long-term debt	156,405	75,580
Less current maturities	(70,000)
Pollution Control Bonds - Variable \| APS \| Maximum
Long-Term Debt and Liquidity Matters [Line Items]
Weighted-average interest rate (as a percent)	0.27%	0.06%
Pollution Control Bonds - Variable \| APS \| Minimum
Long-Term Debt and Liquidity Matters [Line Items]
Weighted-average interest rate (as a percent)	0.03%	0.03%
Pollution Control Bonds - Fixed \| APS
Long-Term Debt and Liquidity Matters [Line Items]
Gross long-term debt	249,300	426,125
Interest Rates, low end of range (as a percent)	0.45%	0.45%
Interest Rates, high end of range (as a percent)	5.75%	5.75%
Total Pollution Control Bonds \| APS
Long-Term Debt and Liquidity Matters [Line Items]
Gross long-term debt	405,705	501,705
Senior unsecured notes \| APS
Long-Term Debt and Liquidity Matters [Line Items]
Gross long-term debt	2,875,000	2,675,000
Interest Rates, low end of range (as a percent)	3.35%	3.35%
Interest Rates, high end of range (as a percent)	8.75%	8.75%
Palo Verde sale leaseback lessor notes \| APS
Long-Term Debt and Liquidity Matters [Line Items]
Palo Verde sale leaseback lessor notes long-term debt excluding current maturities	13,420	38,869
Interest rate (as a percent)	8.00%	8.00%
Term loan facility \| Pinnacle West
Long-Term Debt and Liquidity Matters [Line Items]
Long-term debt	125,000	125,000
Weighted-average interest rate (as a percent)	1.019%	1.269%
Senior unsecured notes maturing through 2015 \| APS
Long-Term Debt and Liquidity Matters [Line Items]
Less current maturities	$ (300,000)

Variable Interest entity long term debt.

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Sum of the carrying values as of the balance sheet date of total long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date.

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Maximum contractual interest rate for funds borrowed, under the debt agreement.

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Minimum contractual interest rate for funds borrowed, under the debt agreement.

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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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The amount of debt premium that was originally recognized at the issuance of the instrument that has yet to be amortized.

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Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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