Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Selected Quarterly Financial Information [Line Items]
OPERATING REVENUES (NOTE 2)	$ 670,391	$ 1,190,787	$ 869,501	$ 740,530	$ 756,376	$ 1,268,034	$ 974,123	$ 692,714	$ 3,471,209	$ 3,691,247	$ 3,565,296
Operations and maintenance	229,857	238,582	227,543	245,634	256,120	246,545	268,397	265,682	941,616	1,036,744	949,107
Operating income	11,997	403,290	196,589	60,084	66,884	433,307	242,162	31,334	671,960	773,687	909,763
Income taxes	(88,537)	53,266	17,080	2,418	6,795	84,333	44,039	(1,265)	(15,773)	133,902	258,272
Net income	68,854	317,149	149,019	22,791	30,949	319,885	171,612	8,094	557,813	530,540	507,949
Net income attributable to common shareholders	$ 63,981	$ 312,276	$ 144,145	$ 17,918	$ 26,076	$ 315,012	$ 166,738	$ 3,221	$ 538,320	$ 511,047	$ 488,456
EARNINGS PER WEIGHTED-AVERAGE COMMON SHARE OUTSTANDING
Net income attributable to common shareholders - basic (in dollars per share)	$ 0.57	$ 2.78	$ 1.28	$ 0.16	$ 0.23	$ 2.81	$ 1.49	$ 0.03	$ 4.79	$ 4.56	$ 4.37
Net income attributable to common shareholders — diluted (in dollars per share)	$ 0.57	$ 2.77	$ 1.28	$ 0.16	$ 0.23	$ 2.80	$ 1.48	$ 0.03	$ 4.77	$ 4.54	$ 4.35
ARIZONA PUBLIC SERVICE COMPANY
Selected Quarterly Financial Information [Line Items]
OPERATING REVENUES (NOTE 2)	$ 670,391	$ 1,190,787	$ 869,501	$ 740,530	$ 756,376	$ 1,267,997	$ 971,963	$ 692,006	$ 3,471,209	$ 3,688,342	$ 3,557,652
Operations and maintenance	226,758	235,440	224,143	240,375	236,281	226,346	251,999	254,601	926,716	969,227	917,983
Operating income	15,124	406,465	200,018	65,377	86,753	453,547	251,590	37,878	686,984	829,768	924,539
Income taxes									(9,572)	144,814	269,168
Net income									584,764	589,758	523,802
Net income attributable to common shareholders	$ 67,949	$ 318,870	$ 150,176	$ 28,276	$ 44,475	$ 338,366	$ 177,825	$ 9,599	$ 565,271	$ 570,265	$ 504,309