Regulatory Matters - Public Utilities General Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue accounts:
Beginning Balance	$ 14,362	$ 11,645	$ 18,451	$ 10,043
Regulatory Asset Increase (Decrease)	1,522	1,570	3,926	3,171
Refunds (Collections) Adjustments	(10,900)	5	(17,393)	6
Ending Balance	4,984	13,220	4,984	13,220
Cost-recovery accounts:
Beginning Balance	19,438	16,492	19,883	15,420
Regulatory Asset Increase (Decrease)	440	1,703	71	2,856
Refunds (Collections) Adjustments	(90)	(98)	(166)	(179)
Ending Balance	19,788	18,097	19,788	18,097
Total
Beginning Balance	33,800	28,137	38,334	25,463
Regulatory Asset Increase (Decrease)	1,962	3,273	3,997	6,027
Refunds (Collections) Adjustments	(10,990)	(93)	(17,559)	(173)
Ending Balance	24,772	31,317	24,772	31,317
MWRAM
Revenue accounts:
Beginning Balance	19,060	13,853	16,866	12,077
Regulatory Asset Increase (Decrease)	2,036	1,424	4,229	3,200
Refunds (Collections) Adjustments	0	1	1	1
Ending Balance	21,096	15,278	21,096	15,278
WCMA
Revenue accounts:
Beginning Balance	(3,061)	666	3,534	666
Regulatory Asset Increase (Decrease)	(1,000)	0	(1,100)	0
Refunds (Collections) Adjustments	(10,900)	2	(17,395)	2
Ending Balance	(14,961)	668	(14,961)	668
Cost of capital memorandum account
Revenue accounts:
Beginning Balance	(1,564)	(1,561)	(1,563)	(1,561)
Regulatory Asset Increase (Decrease)	(4)	(1)	(5)	(1)
Refunds (Collections) Adjustments	0	0	0	0
Ending Balance	(1,568)	(1,562)	(1,568)	(1,562)
All others
Revenue accounts:
Beginning Balance	(73)	(1,313)	(386)	(1,139)
Regulatory Asset Increase (Decrease)	490	147	802	(28)
Refunds (Collections) Adjustments	0	2	1	3
Ending Balance	417	(1,164)	417	(1,164)
Cost-recovery accounts:
Beginning Balance	573	445	445	445
Regulatory Asset Increase (Decrease)	(94)	1	34	1
Refunds (Collections) Adjustments	0	0	0	0
Ending Balance	479	446	479	446
Water supply costs
Cost-recovery accounts:
Beginning Balance	10,789	8,910	10,545	8,123
Regulatory Asset Increase (Decrease)	322	984	566	1,771
Refunds (Collections) Adjustments	0	1	0	1
Ending Balance	11,111	9,895	11,111	9,895
Pension
Cost-recovery accounts:
Beginning Balance	5,006	3,844	4,941	3,478
Regulatory Asset Increase (Decrease)	63	366	128	732
Refunds (Collections) Adjustments	0	0	0	0
Ending Balance	5,069	4,210	5,069	4,210
PRVMA
Cost-recovery accounts:
Beginning Balance	632	1,027	707	1,108
Regulatory Asset Increase (Decrease)	1	0	2	0
Refunds (Collections) Adjustments	(90)	(99)	(166)	(180)
Ending Balance	543	928	543	928
CEMA
Cost-recovery accounts:
Beginning Balance	2,438	2,266	3,245	2,266
Regulatory Asset Increase (Decrease)	148	352	(659)	352
Refunds (Collections) Adjustments	0	0	0	0
Ending Balance	$ 2,586	$ 2,618	$ 2,586	$ 2,618