SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Regulatory Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 25, 2005
Regulatory Assets [Abstract]
Amortization period of depreciation and salary study expenses	five
Goodwill amortization period	50 years
Amortization period of deferred acquisition costs	20 years
Amortization period of deferred franchise costs	80 years
Summary of regulatory assets net of amortization, comprise [Abstract]
Regulatory assets, net	$ 2,304,000	$ 2,393,000
Summary of other deferred assets net of amortization [Abstract]
Debt issuance cost	1,989,000	2,108,000
Investment in Co Bank	2,680,000	2,523,000
Other	503,000	565,000
Other deferred assets	5,172,000	5,196,000
Stock Compensation Plans [Abstract]
Number of share authorize under equity compensation plan (in shares)				500,000
Compensation costs	123,000	108,000	120,000
Summary of fair value of each option grant is estimated using the Black-Scholes-Merton option pricing model [Abstract]
Dividend Yield (in hundredths)	3.63%	4.18%	4.00%
Expected Volatility (in hundredths)	26.16%	25.13%	24.97%
Risk Free Interest Rate (in hundredths)	1.68%	1.87%	3.12%
Expected Term	9 years 4 months 28 days	9 years 5 months 19 days	8 years 4 months 10 days
Base period for calculation of expected dividend yield	12 months
Accounts Receivable [Abstract]
Expense related to allowance for doubtful accounts	200,000	200,000
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable	5,336,000	5,969,000	5,213,000
Less allowance for doubtful accounts	221,000	241,000	216,000
Net accounts receivable	5,115,000	5,728,000	4,997,000
Summary of allowance for doubtful accounts [Abstract]
Beginning balance	241,000	216,000	230,000
Allowance adjustments	180,000	215,000	262,000
Recoveries	115,000	141,000	111,000
Write off of uncollectible accounts	(315,000)	(331,000)	(387,000)
Ending balance	221,000	241,000	216,000
Cash and Cash Equivalents [Abstract]
Maximum maturity period of temporary cash investments consider as cash equivalents	3 months
Customer accounts receivable - water [Member]
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable	3,902,000	3,988,000	3,390,000
Other [Member]
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable	1,434,000	1,981,000	1,823,000
2005 Equity Compensation Plan [Member]
Stock Compensation Plans [Abstract]
Number of share authorize under equity compensation plan (in shares)	375,000
7-Year Rate [Member]
Summary of fair value of each option grant is estimated using the Black-Scholes-Merton option pricing model [Abstract]
Period for risk free interest rate base on treasury constant maturity rate			7 years
10-Year Rate [Member]
Summary of fair value of each option grant is estimated using the Black-Scholes-Merton option pricing model [Abstract]
Period for risk free interest rate base on treasury constant maturity rate	10 years	10 years	10 years
Mountain Hill [Member]
Summary of other deferred assets net of amortization [Abstract]
Other	400,000
Minimum [Member]
Other Deferred Assets [Abstract]
Amortization period of debt issuance costs	10 years
Maximum [Member]
Other Deferred Assets [Abstract]
Amortization period of debt issuance costs	30 years
Maryland [Member]
Regulatory Assets [Abstract]
Amortization period of regulatory rate proceedings and applications	5 years
Delaware [Member]
Regulatory Assets [Abstract]
Amortization period of regulatory rate proceedings and applications	2 years
Postretirement benefit obligation [Member]
Summary of regulatory assets net of amortization, comprise [Abstract]
Regulatory assets, net	438,000	497,000
Deferred income taxes [Member]
Summary of regulatory assets net of amortization, comprise [Abstract]
Regulatory assets, net	476,000	491,000
Goodwill [Member]
Summary of regulatory assets net of amortization, comprise [Abstract]
Regulatory assets, net	333,000	340,000
Deferred acquisition and franchise costs [Member]
Summary of regulatory assets net of amortization, comprise [Abstract]
Regulatory assets, net	792,000	824,000
Expense of rate and regulatory proceedings [Member]
Summary of regulatory assets net of amortization, comprise [Abstract]
Regulatory assets, net	$ 265,000	$ 241,000