Subsequent Event (Details) - USD ($)	1 Months Ended	9 Months Ended
	Oct. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Oct. 13, 2015
Subsequent Event [Line Items]
Proceeds from long-term debt		$ 50,000	$ 0
Cal Water
Subsequent Event [Line Items]
Proceeds from long-term debt		$ 0
Subsequent Event [Member] | Revolving Credit Facility | Cal Water
Subsequent Event [Line Items]
Repayment of debt	$ 72,400,000
Subsequent Event [Member] | First Mortgage Bonds [Member]
Subsequent Event [Line Items]
Debt issued				$ 150,000,000
Debt issuance cost	600,000
Proceeds from long-term debt	$ 99,400,000
Subsequent Event [Member] | First Mortgage Bonds [Member] | First Mortgage Bonds Issue 1 [Member]
Subsequent Event [Line Items]
Debt issued				100,000,000
Subsequent Event [Member] | First Mortgage Bonds [Member] | Series QQQ Bond [Member]
Subsequent Event [Line Items]
Debt issued				$ 50,000,000
Interest rate				3.33%
Subsequent Event [Member] | First Mortgage Bonds [Member] | Series RRR Bond [Member]
Subsequent Event [Line Items]
Debt issued				$ 50,000,000
Interest rate				4.31%
Subsequent Event [Member] | First Mortgage Bonds [Member] | First Mortgage Bonds Issue 2 [Member]
Subsequent Event [Line Items]
Debt issued				$ 50,000,000
Subsequent Event [Member] | First Mortgage Bonds [Member] | Series SSS Bond [Member]
Subsequent Event [Line Items]
Debt issued				$ 40,000,000
Interest rate				4.41%
Subsequent Event [Member] | First Mortgage Bonds [Member] | Series TTT Bond [Member]
Subsequent Event [Line Items]
Debt issued				$ 10,000,000
Interest rate				4.61%