Selected Quarterly Financial Data (Unaudited) (APSC) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated quarterly financial information
Operating revenues	$ 693,122	$ 1,109,475	$ 878,576	$ 620,631	$ 667,892	$ 1,124,841	$ 799,799	$ 648,847	$ 3,301,804	$ 3,241,379	$ 3,189,199
Operations and maintenance	237,141	220,729	216,236	210,663	228,632	210,035	210,590	255,029	884,769	904,286	870,185
Operating income	101,289	447,970	254,489	48,007	78,715	435,017	196,992	35,784	851,755	746,508	714,883
Net income (loss) attributable to common shareholders	22,631	244,823	122,345	(8,257)	12,564	255,359	86,685	(15,135)	381,542	339,473	350,053
ARIZONA PUBLIC SERVICE COMPANY
Consolidated quarterly financial information
Operating revenues	687,031	1,108,623	877,587	620,248	666,504	1,124,057	798,686	647,994	3,293,489	3,237,241
Operations and maintenance	233,320	218,403	213,746	208,447	226,746	207,967	208,597	252,607	873,916	895,917	860,712
Operating income	77,768	296,945	176,821	53,995	70,626	292,783	145,400	45,574	605,529	554,383	549,037
Net income (loss) attributable to common shareholders	$ 26,843	$ 247,831	$ 124,928	$ (4,105)	$ 14,292	$ 246,333	$ 87,705	$ (12,081)	$ 395,497	$ 336,249	$ 335,663