CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands		Total	Common Stock	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	ARIZONA PUBLIC SERVICE COMPANY	ARIZONA PUBLIC SERVICE COMPANY Common Stock	ARIZONA PUBLIC SERVICE COMPANY Additional Paid-In Capital	ARIZONA PUBLIC SERVICE COMPANY Retained Earnings	ARIZONA PUBLIC SERVICE COMPANY Accumulated Other Comprehensive Income (Loss)	ARIZONA PUBLIC SERVICE COMPANY Noncontrolling Interests
Increase (Decrease) in Shareholders' Equity
Stock compensation cumulative effect adjustments	[1]	$ 45,855	$ 40,380		$ 5,475
Beginning balance at Dec. 31, 2015		4,719,457	$ 2,541,668	$ (5,806)	2,092,803	$ (44,748)	$ 135,540	$ 4,814,794	$ 178,162	$ 2,379,696	$ 2,148,493	$ (27,097)	$ 135,540
Beginning Balance (in shares) at Dec. 31, 2015			111,095,402	115,030					71,264,947
Increase (Decrease) in Shareholders' Equity
Net income		461,527			442,034		19,493	481,634			462,141		19,493
Other comprehensive income (loss)		926				926		1,674				1,674
Dividends on common stock		(284,765)			(284,765)			(284,800)			(284,800)
Issuance of common stock		13,982	$ 13,982
Issuance of common stock (in shares)			296,651
Purchase of treasury stock	[2]	(9,087)		$ (9,087)
Purchase of treasury stock (in shares)	[2]			(128,105)
Reissuance of treasury stock for stock-based compensation and other		10,760		$ 10,760
Reissuance of treasury stock for stock-based compensation and other (in shares)				187,818
Equity infusion from Pinnacle West								42,000		42,000
Net capital activities by noncontrolling interests		(22,743)					(22,743)	(22,743)					(22,743)
Ending balance at Dec. 31, 2016		4,935,912	$ 2,596,030	$ (4,133)	2,255,547	(43,822)	132,290	5,037,970	$ 178,162	2,421,696	2,331,245	(25,423)	132,290
Ending Balance (in shares) at Dec. 31, 2016			111,392,053	55,317					71,264,947
Increase (Decrease) in Shareholders' Equity
Stock compensation cumulative effect adjustments	[3]							5,411			5,411
Net income		507,949			488,456		19,493	523,802			504,309		19,493
Other comprehensive income (loss)		(1,180)				(1,180)		(1,560)				(1,560)
Dividends on common stock		(301,492)			(301,492)			(301,600)			(301,600)
Issuance of common stock		18,775	$ 18,775
Issuance of common stock (in shares)			424,117
Purchase of treasury stock	[2]	(17,755)		$ (17,755)
Purchase of treasury stock (in shares)	[2]			(216,911)
Reissuance of treasury stock for stock-based compensation and other		16,264		$ 16,264
Reissuance of treasury stock for stock-based compensation and other (in shares)				207,765
Equity infusion from Pinnacle West								150,000		150,000
Net capital activities by noncontrolling interests		(22,743)					(22,743)	(22,743)					(22,743)
Ending balance at Dec. 31, 2017		$ 5,135,730	$ 2,614,805	$ (5,624)	2,442,511	(45,002)	129,040	5,385,869	$ 178,162	2,571,696	2,533,954	(26,983)	129,040
Ending Balance (in shares) at Dec. 31, 2017		111,816,170	111,816,170	64,463					71,264,947
Increase (Decrease) in Shareholders' Equity
Net income		$ 530,540			511,047		19,493	589,758			570,265		19,493
Other comprehensive income (loss)		5,846				5,846		4,914				4,914
Dividends on common stock		(320,927)			(320,927)			(321,001)			(321,001)
Issuance of common stock		19,460	$ 19,460
Issuance of common stock (in shares)			343,726
Purchase of treasury stock	[2]	(10,338)		$ (10,338)
Purchase of treasury stock (in shares)	[2]			(129,903)
Reissuance of treasury stock for stock-based compensation and other		11,137		$ 11,137
Reissuance of treasury stock for stock-based compensation and other (in shares)				136,231
Equity infusion from Pinnacle West								150,000		150,000
Net capital activities by noncontrolling interests		(22,743)					(22,743)	(22,743)					(22,743)
Reclassification of income tax effects related to new tax reform (See Note 2)		(8,552)			8,552	(8,552)		(5,038)			5,038	(5,038)
Ending balance at Dec. 31, 2018		$ 5,348,705	$ 2,634,265	$ (4,825)	$ 2,641,183	$ (47,708)	$ 125,790	$ 5,786,797	$ 178,162	$ 2,721,696	$ 2,788,256	$ (27,107)	$ 125,790
Ending Balance (in shares) at Dec. 31, 2018		112,159,896	112,159,896	58,135					71,264,947

[1] During 2016, we adopted new stock-based compensation accounting guidance.

[2] Primarily represents shares of common stock withheld from certain stock awards for tax purposes.

[3] During 2016, we adopted new stock-based compensation accounting guidance.