CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands		Total	Common Stock	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	APS	APS Common Stock	APS Additional Paid-In Capital	APS Retained Earnings	APS Accumulated Other Comprehensive Income (Loss)	APS Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2019			112,540,126	103,546					71,264,947
Balance at beginning of period at Dec. 31, 2019		$ 5,553,188	$ 2,659,561	$ (9,427)	$ 2,837,610	$ (57,096)	$ 122,540	$ 5,998,803	$ 178,162	$ 2,721,696	$ 3,011,927	$ (35,522)	$ 122,540
Increase (Decrease) in Shareholders' Equity
Net Income		34,866			29,993		4,873	40,218			35,345		4,873
Other comprehensive income (loss)		1,517				1,517		1,325				1,325
Dividends on common stock		8			8
Issuance of common stock (in shares)			23,484
Issuance of common stock		4,826	$ 4,826
Purchase of treasury stock (in shares)	[1]			(20,724)
Purchase of treasury stock	[1]	(2,086)		$ (2,086)
Reissuance of treasury stock for stock-based compensation and other (in shares)				51,968
Reissuance of treasury stock for stock-based compensation and other		4,513		$ 4,513
Other		0			1		1	(2)			(3)		1
Ending balance (in shares) at Mar. 31, 2020			112,563,610	72,302					71,264,947
Balance at end of period at Mar. 31, 2020		$ 5,596,832	$ 2,664,387	$ (7,000)	2,867,610	(55,579)	127,414	6,040,344	$ 178,162	2,721,696	3,047,269	(34,197)	127,414
Beginning balance (in shares) at Dec. 31, 2020		112,760,051	112,760,051	72,006					71,264,947
Balance at beginning of period at Dec. 31, 2020		$ 5,752,793	$ 2,677,482	$ (6,289)	3,025,106	(62,796)	119,290	6,345,185	$ 178,162	2,871,696	3,216,955	(40,918)	119,290
Increase (Decrease) in Shareholders' Equity
Net Income		40,514			35,641		4,873	40,160			35,287		4,873
Other comprehensive income (loss)		1,284				1,284		927				927
Dividends on common stock		5			5
Issuance of common stock (in shares)			31,514
Issuance of common stock		9,570	$ 9,570
Purchase of treasury stock (in shares)	[1]			(17,437)
Purchase of treasury stock	[1]	(1,333)		$ (1,333)
Reissuance of treasury stock for stock-based compensation and other (in shares)				45,105
Reissuance of treasury stock for stock-based compensation and other		3,846		$ 3,846
Other		$ 1					1	3			2		1
Ending balance (in shares) at Mar. 31, 2021		112,791,565	112,791,565	44,338					71,264,947
Balance at end of period at Mar. 31, 2021		$ 5,806,680	$ 2,687,052	$ (3,776)	$ 3,060,752	$ (61,512)	$ 124,164	$ 6,386,275	$ 178,162	$ 2,871,696	$ 3,252,244	$ (39,991)	$ 124,164

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