Summary of Significant Accounting Policies: (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 registrant	Mar. 31, 2012
Basis of Presentation:
Number of registrants filing combined report	2
Sales and Use Taxes:
Non-income tax assessments accounted on a gross basis	$ 4,148,000	$ 4,105,000
GSWC
Sales and Use Taxes:
Franchise fees billed to customers and recorded as operating revenue	811,000	784,000
Non-income tax assessments accounted on a gross basis	3,716,000	3,743,000
GSWC | Purchase, production, distribution and sale of water
Nature of Operations:
Number of customers served	256,000
GSWC | Electricity distribution
Nature of Operations:
Number of customers served	23,000
ASUS
Sales and Use Taxes:
Non-income tax assessments accounted on a gross basis	162,000	155,000
ASUS | Contracts
Nature of Operations:
Period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases	50 years
AWR | Syndicated Credit Facility
Related Party Transactions
Maximum borrowing capacity on line of credit	$ 100,000,000