Other Income and Other Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Other income:
Interest income	$ 1,691	$ 1,687	$ 3,333	$ 3,635
Miscellaneous	(9)	40	53	43
Total other income	1,682	12,207	3,386	24,636
Other expense:
Non-operating costs	(3,701)	(4,102)	(6,154)	(6,039)
Investment losses — net	(575)	(431)	(1,256)	(774)
Miscellaneous	(308)	(651)	(596)	(2,224)
Total other expense	(4,584)	(5,184)	(8,006)	(9,037)
APS
Other income:
Interest income	1,396	1,047	2,495	2,528
Miscellaneous	0	36	53	37
Total other income	1,396	11,563	2,548	23,523
Other expense:
Non-operating costs	(2,477)	(3,615)	(4,038)	(5,392)
Miscellaneous	(309)	(646)	(596)	(2,219)
Total other expense	(2,786)	(4,261)	(4,634)	(7,611)
SCR deferral
Other income:
Debt return	0	4,089	0	8,175
SCR deferral | APS
Other income:
Debt return	0	4,089	0	8,175
Octotillo modernization project
Other income:
Debt return	0	6,391	0	12,783
Octotillo modernization project | APS
Other income:
Debt return	$ 0	$ 6,391	$ 0	$ 12,783