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, 2014			110,649,762	78,400					71,264,947
Balance at end of period at Dec. 31, 2014		$ 4,519,102	$ 2,512,970	$ (3,401)	$ 1,926,065	$ (68,141)	$ 151,609	$ 4,629,852	$ 178,162	$ 2,379,696	$ 1,968,718	$ (48,333)	$ 151,609
Increase (Decrease) in Shareholders' Equity
Net income		410,212			396,140		14,072	420,489			406,417		14,072
Other comprehensive income		4,151				4,151		4,293				4,293
Dividends on common stock		(131,818)			(131,818)			(131,800)			(131,800)
Other								1			1
Issuance of common stock (in shares)			250,868
Issuance of common stock		16,049	$ 16,049
Purchase of treasury stock (in shares)	[1]			(93,280)
Purchase of treasury stock	[1]	(6,096)		$ (6,096)
Reissuance of treasury stock for stock-based compensation and other (in shares)				118,121
Reissuance of treasury stock for stock-based compensation and other		7,732		$ 7,732
Capital activities by noncontrolling interests		(28,013)					(28,013)	(28,013)					(28,013)
Ending balance (in shares) at Sep. 30, 2015			110,900,630	53,559					71,264,947
Balance at beginning of period at Sep. 30, 2015		4,791,319	$ 2,529,019	$ (1,765)	2,190,387	(63,990)	137,668	4,894,822	$ 178,162	2,379,696	2,243,336	(44,040)	137,668
Increase (Decrease) in Shareholders' Equity
Net income		261,978						266,049
Other comprehensive income		1,610						1,611
Ending balance (in shares) at Sep. 30, 2015			110,900,630	53,559					71,264,947
Balance at beginning of period at Sep. 30, 2015		$ 4,791,319	$ 2,529,019	$ (1,765)	2,190,387	(63,990)	137,668	4,894,822	$ 178,162	2,379,696	2,243,336	(44,040)	137,668
Beginning balance (in shares) at Dec. 31, 2015		111,095,402	111,095,402	115,030					71,264,947
Balance at end 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)
Capital activities by noncontrolling interests		$ (11,371)					(11,371)	(11,371)					(11,371)
Ending balance (in shares) at Sep. 30, 2016		111,220,370	111,220,370	1,900					71,264,947
Balance at beginning 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	111,220,370	1,900					71,264,947
Balance at beginning 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

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