Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Selected Quarterly Financial Information [Line Items]
OPERATING REVENUES	$ 756,376	$ 1,268,034	$ 974,123	$ 692,714	$ 759,659	$ 1,183,322	$ 944,587	$ 677,728	$ 3,691,247	$ 3,565,296	$ 3,498,682
Operations and maintenance	256,120	246,545	268,397	265,682	271,212	230,839	220,985	226,071	1,036,744	949,107	931,692
Operating income	66,884	433,307	242,162	31,334	85,547	459,548	297,257	67,411	773,687	909,763	835,611
Income taxes	6,795	84,333	44,039	(1,265)	20,775	144,319	88,967	4,211	133,902	258,272	236,411
Net income	30,949	319,885	171,612	8,094	26,502	280,945	172,317	28,185	530,540	507,949	461,527
Net income attributable to common shareholders	$ 26,076	$ 315,012	$ 166,738	$ 3,221	$ 21,629	$ 276,072	$ 167,443	$ 23,312	$ 511,047	$ 488,456	$ 442,034
EARNINGS PER WEIGHTED-AVERAGE COMMON SHARE OUTSTANDING
Net income attributable to common shareholders - basic (in dollars per share)	$ 0.23	$ 2.81	$ 1.49	$ 0.03	$ 0.19	$ 2.47	$ 1.50	$ 0.21	$ 4.56	$ 4.37	$ 3.97
Net income attributable to common shareholders — diluted (in dollars per share)	$ 0.23	$ 2.80	$ 1.48	$ 0.03	$ 0.19	$ 2.46	$ 1.49	$ 0.21	$ 4.54	$ 4.35	$ 3.95
ARIZONA PUBLIC SERVICE COMPANY
Selected Quarterly Financial Information [Line Items]
OPERATING REVENUES	$ 756,376	$ 1,267,997	$ 971,963	$ 692,006	$ 757,811	$ 1,178,846	$ 943,406	$ 677,589	$ 3,688,342	$ 3,557,652	$ 3,498,090
Operations and maintenance	236,281	226,346	251,999	254,601	260,826	222,374	215,775	219,008	969,227	917,983	902,467
Operating income	86,753	453,547	251,590	37,878	91,912	465,658	296,700	70,269	829,768	924,539	858,485
Income taxes									144,814	269,168	245,842
Net income									589,758	523,802	481,634
Net income attributable to common shareholders	$ 44,475	$ 338,366	$ 177,825	$ 9,599	$ 27,783	$ 284,256	$ 169,108	$ 23,162	$ 570,265	$ 504,309	$ 462,141