Other Income and Other Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Other income:
Interest income	$ 1,785	$ 1,602	$ 5,118	$ 5,236
Miscellaneous	434	4	487	48
Total other income	2,219	12,083	5,605	36,719
Other expense:
Non-operating costs	(2,956)	(2,973)	(9,110)	(9,013)
Investment losses — net	(935)	(704)	(2,191)	(1,478)
Miscellaneous	(2,854)	(2,505)	(3,450)	(4,728)
Total other expense	(6,745)	(6,182)	(14,751)	(15,219)
APS
Other income:
Interest income	1,402	1,118	3,897	3,645
Miscellaneous	259	2	312	40
Total other income	1,661	11,597	4,209	35,120
Other expense:
Non-operating costs	(2,369)	(1,892)	(6,407)	(7,284)
Miscellaneous	(654)	(304)	(1,250)	(2,523)
Total other expense	(3,023)	(2,196)	(7,657)	(9,807)
SCR deferral
Other income:
Debt return	0	4,091	0	12,266
SCR deferral | APS
Other income:
Debt return	0	4,091	0	12,266
Octotillo modernization project
Other income:
Debt return	0	6,386	0	19,169
Octotillo modernization project | APS
Other income:
Debt return	$ 0	$ 6,386	$ 0	$ 19,169