Summary of Significant Accounting Policies (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Revenue
Markup for return or profit for cost-recovery expenses	$ 0
Maturity period of commercial paper	90 days
Minimum collection period after net receivable balances were recognized in which the Company defers net WRAM and MCBA operating revenues and associated costs	24 months
Maximum collection period in which deferred net WRAM and MCBA revenues and associated costs will be recognized	24 months
Unearned revenue liability	1,500,000	1,500,000
Regulatory Assets and Liabilities
Net short-term receivable	45,073,000	30,887,000
Net long-term receivable	277,476,000	251,681,000
Net short-term payable	6,791,000	1,827,000
Net long-term payable	91,713,000	86,455,000
Minimum
Regulatory Assets and Liabilities
Expected collection period for undercollected net WRAM and MCBA receivables	12 months
Maximum
Regulatory Assets and Liabilities
Expected collection period for undercollected net WRAM and MCBA receivables	18 months
Net WRAM and MCBA accounts payable
Regulatory Assets and Liabilities
Net short-term payable	423,000	1,032,000
Net long-term payable	1,385,000	906,000
Total payable	1,808,000	1,938,000
Net WRAM and MCBA accounts receivable
Regulatory Assets and Liabilities
Net short-term receivable	27,927,000	30,887,000
Net long-term receivable	16,608,000	15,423,000
Total receivable	$ 44,535,000	$ 46,310,000