Revenue from Contract with Customer (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 8,685	$ 8,253	$ 35,471	$ 35,515
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8,685	8,253	35,471	35,515
Deferred revenue - ICFA	17,372	17,358	17,372	17,358
Contract with Customer, Asset, after Allowance for Credit Loss	1,717	1,633	1,717	1,633
Contract with Customer, Liability	17,959	17,698	17,959	17,698
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue - ICFA	17,372	17,358	$ 17,372	17,358
Revenue, Performance Obligation, Description of Payment Terms			within 15 days of billing
Regulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	8,670	8,172	$ 35,406	32,998
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8,670	8,172	35,406	32,998
Contract with Customer, Liability	587	340	587	340
Unregulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	15	81	65	2,517
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	15	81	65	2,517
Water [Member]
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	3,799	3,570	16,143	15,344
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	3,799	3,570	16,143	15,344
waste water and recycled water
Disaggregation of Revenue [Line Items]
Contract with Customer, Asset, after Allowance for Credit Loss	926	838	926	838
waste water and recycled water \| Regulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	4,871	4,602	19,263	17,654
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,871	4,602	19,263	17,654
ICFA \| Unregulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	0	68	0	2,456
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	68	0	2,456
rental revenue \| Unregulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	15	13	64	58
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	15	13	64	58
Other miscellaneous revenues \| Unregulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	1	3
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	1	3
Water Services
Disaggregation of Revenue [Line Items]
Contract with Customer, Asset, after Allowance for Credit Loss	791	795	791	795
Residential [Member] \| Water [Member]
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	2,867	2,731	11,519	10,931
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,867	2,731	11,519	10,931
Residential [Member] \| waste water and recycled water \| Regulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	4,355	4,124	17,053	15,581
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,355	4,124	17,053	15,581
irrigation \| Water [Member]
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	556	486	3,008	2,685
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	556	486	3,008	2,685
commercial \| Water [Member]
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	185	174	768	804
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	185	174	768	804
commercial \| waste water and recycled water \| Regulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	230	201	908	803
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	230	201	908	803
construction \| Water [Member]
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	48	31	152	231
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	48	31	152	231
other water services \| Water [Member]
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	143	148	696	693
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	143	148	696	693
recycledwater \| waste water and recycled water \| Regulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	205	178	922	876
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	205	178	922	876
other wastewater \| waste water and recycled water \| Regulated Operation
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	81	99	380	394
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 81	$ 99	$ 380	$ 394

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of deferred income and obligation to transfer product and service to customer for which consideration has been received or is receivable, classified as noncurrent.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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