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Summary of Significant Accounting Policies: (Details) customer in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) customer registrant	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Summary of significant accounting policies
Operating lease right-of-use assets	$ 6,276,000		$ 0
Basis of Presentation:
Number of registrants filing combined report \| registrant	2
Related Party Transactions
Notes payable to bank	$ 151,500,000		95,500,000
Total lease obligations	6,466,000
AWR \| Syndicated Credit Facility
Related Party Transactions
Maximum borrowing capacity on line of credit	200,000,000
GOLDEN STATE WATER COMPANY
Summary of significant accounting policies
Operating lease right-of-use assets	5,367,000		$ 0
Related Party Transactions
Payments to affiliate for corporate office administrative and general costs	1,100,000	$ 1,000,000
GOLDEN STATE WATER COMPANY \| Notes Payable 6.7 Percent Due 2019 [Member]
Related Party Transactions
Debt and Capital Lease Obligations	$ 40,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.70%
GOLDEN STATE WATER COMPANY \| Water Service Utility Operations
Nature of Operations:
Number of customers \| customer	260
GOLDEN STATE WATER COMPANY \| Electric Service Utility Operations
Nature of Operations:
Number of customers \| customer	24
ASUS \| Contracted Services
Nature of Operations:
Period of fixed price contracts to operate and maintain water systems at various military bases	50 years
Sales \| GOLDEN STATE WATER COMPANY \| Water Service Utility Operations
Nature of Operations:
Concentration Risk, Percentage	90.00%	90.00%
Sales \| GOLDEN STATE WATER COMPANY \| Electric Service Utility Operations
Nature of Operations:
Concentration Risk, Percentage	85.00%	85.00%
Minimum [Member] \| AWR \| Syndicated Credit Facility
Related Party Transactions
Line of Credit Facility, Current Borrowing Capacity	$ 150,000,000