Other Income and Other Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Other income:
Interest income	$ 1,642	$ 1,948
Miscellaneous	62	3
Total other income	1,704	12,429
Other expense:
Non-operating costs	(2,453)	(1,937)
Investment losses — net	(681)	(343)
Miscellaneous	(288)	(1,573)
Total other expense	(3,422)	(3,853)
APS
Other income:
Interest income	1,099	1,481
Miscellaneous	53	1
Total other income	1,152	11,960
Other expense:
Non-operating costs	(1,561)	(1,778)
Miscellaneous	(288)	(1,572)
Total other expense	(1,849)	(3,350)
SCR deferral
Other income:
Debt return	0	4,086
SCR deferral | APS
Other income:
Debt return	0	4,086
Octotillo modernization project
Other income:
Debt return	0	6,392
Octotillo modernization project | APS
Other income:
Debt return	$ 0	$ 6,392