Income Taxes (APSC) (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Tabular reconciliation of the total amounts of unrecognized tax benefits, excluding interest and penalties, at the beginning and end of the year
Total unrecognized tax benefits at the beginning of the year	$ 201,216,000	$ 127,595,000	$ 201,216,000	$ 63,318,000
Additions for tax positions of the current year		10,915,000	7,551,000	44,094,000
Additions for tax positions of prior years				98,942,000
Reductions for tax positions of prior years for:
Changes in judgment		(1,555,000)	(11,017,000)
Settlements with taxing authorities	(62,000,000)	(124,000)	(62,199,000)	(4,089,000)
Lapses of applicable statute of limitations		(826,000)	(7,956,000)	(1,049,000)
Total unrecognized tax benefits at the end of the year		136,005,000	127,595,000	201,216,000
Unrecognized tax benefits if recognized, would decrease effective tax rate		8,000,000	7,000,000	16,000,000
Pre-tax interest expense (benefit) related to unrecognized tax benefits		3,000,000	(2,000,000)	2,000,000
Accrued liabilities for interest related to unrecognized tax benefits		9,000,000	6,000,000	8,000,000
Interest income to be received on the overpayment of income taxes for certain adjustments that we have filed, or will file, with the IRS		4,000,000
Settlements with taxing authorities	62,000,000	124,000	62,199,000	4,089,000
Net decrease in uncertain tax positions which decreased our effective tax rate	3,000,000
Net interest benefits through the effective tax rate	4,000,000
ARIZONA PUBLIC SERVICE COMPANY
Tabular reconciliation of the total amounts of unrecognized tax benefits, excluding interest and penalties, at the beginning and end of the year
Total unrecognized tax benefits at the beginning of the year	199,887,000	126,698,000	199,887,000	62,409,000
Additions for tax positions of the current year		10,915,000	7,551,000	44,094,000
Additions for tax positions of prior years				98,269,000
Reductions for tax positions of prior years for:
Changes in judgment		(1,555,000)	(10,964,000)
Settlements with taxing authorities	(62,000,000)	(124,000)	(61,820,000)	(4,089,000)
Lapses of applicable statute of limitations		(110,000)	(7,956,000)	(796,000)
Total unrecognized tax benefits at the end of the year		135,824,000	126,698,000	199,887,000
Unrecognized tax benefits if recognized, would decrease effective tax rate		8,000,000	6,000,000	15,000,000
Pre-tax interest expense (benefit) related to unrecognized tax benefits		3,000,000	(2,000,000)	2,000,000
Accrued liabilities for interest related to unrecognized tax benefits		9,000,000	6,000,000	8,000,000
Interest income to be received on the overpayment of income taxes for certain adjustments that we have filed, or will file, with the IRS		4,000,000
Settlements with taxing authorities	62,000,000	124,000	61,820,000	4,089,000
Net decrease in uncertain tax positions which decreased our effective tax rate	3,000,000
Net interest benefits through the effective tax rate	$ 4,000,000