CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) - 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
Beginning balance (in shares) at Dec. 31, 2015			111,095,402	115,030					71,264,947
Balance at beginning of period 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
Increase (Decrease) in Shareholders' Equity
Net income		403,408			388,788		14,620	418,281			403,661		14,620
Other comprehensive income		2,602				2,602		2,737				2,737
Dividends on common stock		(138,947)			(138,947)			(139,001)			(139,001)
Issuance of common stock (in shares)			124,968
Issuance of common stock		11,311	$ 11,311
Purchase of treasury stock (in shares)	[1]			(71,962)
Purchase of treasury stock	[1]	(4,880)		$ (4,880)
Reissuance of treasury stock for stock-based compensation and other (in shares)				185,092
Reissuance of treasury stock for stock-based compensation and other		10,555		$ 10,556	(1)		0
Capital activities by noncontrolling interests		(11,371)					(11,371)	(11,371)					(11,371)
Ending balance (in shares) at Sep. 30, 2016			111,220,370	1,900					71,264,947
Balance at end of period at Sep. 30, 2016		4,992,135	$ 2,552,979	$ (130)	2,342,643	(42,146)	138,789	5,085,440	$ 178,162	2,379,696	2,413,153	(24,360)	138,789
Increase (Decrease) in Shareholders' Equity
Net income		267,900						274,093
Other comprehensive income		1,573						1,568
Ending balance (in shares) at Sep. 30, 2016			111,220,370	1,900					71,264,947
Balance at end of period at Sep. 30, 2016		$ 4,992,135	$ 2,552,979	$ (130)	2,342,643	(42,146)	138,789	5,085,440	$ 178,162	2,379,696	2,413,153	(24,360)	138,789
Beginning balance (in shares) at Dec. 31, 2016		111,392,053	111,392,053	55,317					71,264,947
Balance at beginning of period 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
Increase (Decrease) in Shareholders' Equity
Net income		481,447			466,827		14,620	491,143			476,523		14,620
Other comprehensive income		1,705				1,705		1,807				1,807
Other								1			0		1
Dividends on common stock		(146,204)			(146,204)			(146,198)			(146,198)
Issuance of common stock (in shares)			274,823
Issuance of common stock		12,795	$ 12,795
Purchase of treasury stock (in shares)	[1]			(162,312)
Purchase of treasury stock	[1]	(12,964)		$ (12,964)
Reissuance of treasury stock for stock-based compensation and other (in shares)				207,765
Reissuance of treasury stock for stock-based compensation and other		16,288		$ 16,264	23		1
Capital activities by noncontrolling interests		$ (11,372)					(11,372)	(11,372)					(11,372)
Ending balance (in shares) at Sep. 30, 2017		111,666,876	111,666,876	9,864					71,264,947.000
Balance at end of period at Sep. 30, 2017		$ 5,277,607	$ 2,608,825	$ (833)	2,576,193	(42,117)	135,539	5,373,351	$ 178,162	2,421,696	2,661,570	(23,616)	135,539
Increase (Decrease) in Shareholders' Equity
Net income		280,945						289,129
Other comprehensive income		$ 1,509						1,496
Ending balance (in shares) at Sep. 30, 2017		111,666,876	111,666,876	9,864					71,264,947.000
Balance at end of period at Sep. 30, 2017		$ 5,277,607	$ 2,608,825	$ (833)	$ 2,576,193	$ (42,117)	$ 135,539	$ 5,373,351	$ 178,162	$ 2,421,696	$ 2,661,570	$ (23,616)	$ 135,539

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