CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
NET INCOME	$ 198,459	$ 149,019	$ 233,325	$ 171,810
Derivative instruments:
Net unrealized gain, net of tax expense	(1,549)	0	(1,257)	0
Reclassification of net realized loss, net of tax benefit	262	404	282	732
Pension and other postretirement benefits activity, net of tax expense	(1,009)	(1,539)	196	(660)
Total other comprehensive income (loss)	(2,296)	(1,135)	(779)	72
COMPREHENSIVE INCOME	196,163	147,884	232,546	171,882
Less: Comprehensive income attributable to noncontrolling interests	4,874	4,874	9,747	9,747
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	191,289	143,010	222,799	162,135
APS
NET INCOME	201,992	155,050	242,210	188,199
Derivative instruments:
Net unrealized gain, net of tax expense	0	0	292	0
Reclassification of net realized loss, net of tax benefit	262	404	282	732
Pension and other postretirement benefits activity, net of tax expense	(1,090)	(1,653)	(77)	(901)
Total other comprehensive income (loss)	(828)	(1,249)	497	(169)
COMPREHENSIVE INCOME	201,164	153,801	242,707	188,030
Less: Comprehensive income attributable to noncontrolling interests	4,874	4,874	9,747	9,747
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 196,290	$ 148,927	$ 232,960	$ 178,283