The York Water Company (YORW) 10-K 10 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Mar. 09, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	YORK WATER CO
Entity Central Index Key	108985
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$267,065,786
Entity Common Stock, Shares Outstanding		12,837,661
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14

Balance_Sheets

Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
ASSETS
UTILITY PLANT, at original cost	$316,525	$301,570
Plant acquisition adjustments	-3,522	-2,900
Accumulated depreciation	-59,809	-54,433
Net utility plant	253,194	244,237
OTHER PHYSICAL PROPERTY:
Net of accumulated depreciation of $286 in 2014 and $240 in 2013	765	763
CURRENT ASSETS:
Cash and cash equivalents	1,488	7,565
Restricted cash	7	95
Accounts receivable, net of reserves of $325 in 2014 and $320 in 2013	3,991	3,772
Unbilled revenues	2,377	2,286
Recoverable income taxes	957	0
Materials and supplies inventories, at cost	771	722
Prepaid expenses	584	573
Deferred income taxes	1,058	219
Total current assets	11,233	15,232
OTHER LONG-TERM ASSETS:
Deferred debt expense	2,573	2,187
Notes receivable	266	306
Deferred regulatory assets	32,614	16,123
Other assets	3,694	3,681
Total other long-term assets	39,147	22,297
Total Assets	304,339	282,529
COMMON STOCKHOLDERS' EQUITY:
Common stock, no par value, authorized 46,500,000 shares, issued and outstanding 12,830,521 shares in 2014 and 12,979,281 shares in 2013	77,556	80,545
Retained earnings	27,007	22,966
Total common stockholders' equity	104,563	103,511
PREFERRED STOCK, authorized 500,000 shares, no shares issued	0	0
LONG-TERM DEBT, excluding current portion	84,842	84,885
COMMITMENTS
CURRENT LIABILITIES:
Current portion of long-term debt	43	43
Accounts payable	1,589	1,758
Dividends payable	1,647	1,606
Accrued compensation and benefits	1,078	1,125
Accrued income taxes	0	1,724
Accrued interest	1,027	1,064
Other accrued expenses	546	523
Total current liabilities	5,930	7,843
DEFERRED CREDITS:
Customers' advances for construction	10,712	11,636
Deferred income taxes	46,024	34,594
Deferred employee benefits	13,727	7,903
Other deferred credits	7,489	2,231
Total deferred credits	77,952	56,364
Contributions in aid of construction	31,052	29,926
Total Stockholders' Equity and Liabilities	$304,339	$282,529

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
OTHER PHYSICAL PROPERTY:
Other physical property, accumulated depreciation	$286	$240
CURRENT ASSETS:
Receivables, reserves	$325	$320
COMMON STOCKHOLDERS' EQUITY:
Common stock, par value (in dollars per share)	$0	$0
Common stock, authorized (in shares)	46,500,000	46,500,000
Common stock, issued (in shares)	12,830,521	12,979,281
Common stock, outstanding (in shares)	12,830,521	12,979,281
Preferred stock, authorized (in shares)	500,000	500,000
Preferred stock, issued (in shares)	0	0

Statements_of_Income

Statements of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
OPERATING REVENUES:
Residential	$29,079	$26,796	$26,114
Commercial and industrial	13,267	12,299	12,114
Other	3,554	3,288	3,219
Operating revenues	45,900	42,383	41,447
OPERATING EXPENSES:
Operation and maintenance	7,968	7,350	7,221
Administrative and general	8,812	7,406	7,303
Depreciation and amortization	5,932	5,744	5,170
Taxes other than income taxes	1,111	1,122	1,180
Operating expenses	23,823	21,622	20,874
Operating income	22,077	20,761	20,573
OTHER INCOME (EXPENSES):
Interest on debt	-5,087	-5,244	-5,249
Allowance for funds used during construction	210	82	105
Gain on sale of land	316	0	0
Other income (expenses), net	-1,155	-133	-520
Other income (expenses)	-5,716	-5,295	-5,664
Income before income taxes	16,361	15,466	14,909
Income taxes	4,877	5,812	5,606
Net Income	$11,484	$9,654	$9,303
Basic Earnings Per Share (in dollars per share)	$0.89	$0.75	$0.72
Cash Dividends Declared Per Share (in shares)	$0.58	$0.56	$0.54

Statements_of_Common_Stockhold

Statements of Common Stockholders' Equity (USD $)	Common Stock [Member]	Retained Earnings [Member]	Total
In Thousands, except Share data
Balance at Dec. 31, 2011	$77,113	$18,152	$95,265
Balance (in shares) at Dec. 31, 2011	12,791,671
Net income	0	9,303	9,303
Dividends	0	-6,929	-6,929
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans	2,186	0	2,186
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans (in shares)	126,962
Balance at Dec. 31, 2012	79,299	20,526	99,825
Balance (in shares) at Dec. 31, 2012	12,918,633
Net income	0	9,654	9,654
Dividends	0	-7,214	-7,214
Retirement of common stock	-1,772	0	-1,772
Retirement of common stock (in shares)	-94,414		-94,414
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans	3,018	0	3,018
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans (in shares)	155,062
Balance at Dec. 31, 2013	80,545	22,966	103,511
Balance (in shares) at Dec. 31, 2013	12,979,281		12,979,281
Net income	0	11,484	11,484
Dividends	0	-7,443	-7,443
Retirement of common stock	-5,692	0	-5,692
Retirement of common stock (in shares)	-282,570		-282,570
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans	2,703	0	2,703
Issuance of common stock under dividend reinvestment, direct stock and employee stock purchase plans (in shares)	133,810
Balance at Dec. 31, 2014	$77,556	$27,007	$104,563
Balance (in shares) at Dec. 31, 2014	12,830,521		12,830,521

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$11,484	$9,654	$9,303
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of land	-316	0	0
Depreciation and amortization	5,932	5,744	5,170
Increase in deferred income taxes	4,753	1,939	2,311
Other	199	213	208
Changes in assets and liabilities:
(Increase) decrease in accounts receivable and unbilled revenues	-632	11	-699
(Increase) decrease in recoverable income taxes	-957	0	197
Increase in materials and supplies, prepaid expenses, regulatory and other assets	-11,438	-1,056	-650
Increase in accounts payable, accrued compensation and benefits, accrued expenses, deferred employee benefits, and other deferred credits	11,502	306	486
Increase (decrease) in accrued interest and taxes	-1,761	1,627	96
Net cash provided by operating activities	18,766	18,438	16,422
CASH FLOWS FROM INVESTING ACTIVITIES:
Utility plant additions, including debt portion of allowance for funds used during construction of $117 in 2014, $46 in 2013 and $59 in 2012	-14,139	-9,852	-11,543
Acquisitions of water and wastewater systems	-369	-28	-661
Proceeds from sale of land	346	0	0
Decrease in compensating balance	0	500	0
Decrease in notes receivable	40	32	30
Net cash used in investing activities	-14,122	-9,348	-12,174
CASH FLOWS FROM FINANCING ACTIVITIES:
Customers' advances for construction and contributions in aid of construction	638	733	780
Repayments of customer advances	-419	-313	-304
Proceeds of long-term debt issues	14,880	0	0
Debt issuance costs	-506	0	0
Repayments of long-term debt	-14,923	-47	-42
Repurchase of common stock	-5,692	-1,772	0
Issuance of common stock	2,703	3,018	2,186
Dividends paid	-7,402	-7,156	-6,862
Net cash used in financing activities	-10,721	-5,537	-4,242
Net change in cash and cash equivalents	-6,077	3,553	6
Cash and cash equivalents at beginning of period	7,565	4,012	4,006
Cash and cash equivalents at end of period	1,488	7,565	4,012
Cash paid during the period for:
Interest, net of amounts capitalized	5,007	5,198	5,192
Income taxes	$2,808	$1,921	$2,703
Supplemental schedule of non-cash investing and financing activities:
Accounts payable includes $833 in 2014, $974 in 2013 and $674 in 2012 for the construction of utility plant.

Statements_of_Cash_Flows_Paren

Statements of Cash Flows (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM INVESTING ACTIVITIES:
Utility plant additions, debt portion of allowance for funds used during construction	$117	$46	$59
Supplemental schedule of non-cash investing and financing activities:
Accounts payable, construction of utility plant	$833	$974	$674

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies
Significant Accounting Policies	1	Significant Accounting Policies
	The primary business of The York Water Company is to impound, purify and distribute water.  The Company also operates two wastewater collection and treatment systems.  The Company operates within its franchised territory located in York and Adams Counties, Pennsylvania, and is subject to regulation by the Pennsylvania Public Utility Commission, or PPUC.
	The following summarizes the significant accounting policies employed by The York Water Company.
	Utility Plant and Depreciation
	The cost of additions includes contracted cost, direct labor and fringe benefits, materials, overhead and, for certain utility plant, allowance for funds used during construction. In accordance with regulatory accounting requirements, water and wastewater systems acquired are recorded at estimated original cost of utility plant when first devoted to utility service and the applicable depreciation is recorded to accumulated depreciation. The difference between the estimated original cost less applicable accumulated depreciation, and the purchase price is recorded as an acquisition adjustment within utility plant as permitted by the PPUC.  At December 31, 2014 and 2013, utility plant includes a net credit acquisition adjustment of $3,522 and $2,900, respectively.  For those amounts approved by the PPUC, the net acquisition adjustment is being amortized over the remaining life of the respective assets. Certain amounts are still awaiting approval from the PPUC before amortization will commence.  Amortization amounted to $54 in 2014, $50 in 2013, and $50 in 2012.
	Upon normal retirement of depreciable property, the estimated or actual cost of the asset is credited to the utility plant account, and such amounts, together with the cost of removal less salvage value, are charged to the reserve for depreciation. To the extent the Company recovers cost of removal or other retirement costs through rates after the retirement costs are incurred, a regulatory asset is reported. Gains or losses from abnormal retirements are reflected in income currently.
	The straight-line remaining life method is used to compute depreciation on utility plant cost, exclusive of land and land rights. Annual provisions for depreciation of transportation and mechanical equipment included in utility plant are computed on a straight-line basis over the estimated service lives. Such provisions are charged to clearing accounts and apportioned therefrom to operating expenses and other accounts in accordance with the Uniform System of Accounts as prescribed by the PPUC.
	The Company charges to maintenance expense the cost of repairs and replacements and renewals of minor items of property. Maintenance of transportation equipment is charged to clearing accounts and apportioned therefrom in a manner similar to depreciation. The cost of replacements, renewals and betterments of units of property is capitalized to the utility plant accounts.
	The following remaining lives are used for financial reporting purposes:
			December 31,				Approximate range
	Utility Plant Asset Category		2014		2013		of remaining lives
	Mains and accessories		$	164,627	$	157,113	10 – 84 years
	Services, meters and hydrants			63,479		61,206	19 – 55 years
	Operations structures, reservoirs and water tanks			43,654		42,692	11 – 41 years
	Pumping and treatment equipment			25,616		23,411	3 – 31 years
	Office, transportation and operating equipment			11,216		10,994	3 – 21 years
	Land and other non-depreciable assets			3,166		3,127	-
	Utility plant in service			311,758		298,543
	Construction work in progress			4,767		3,027	-
	Total Utility Plant		$	316,525	$	301,570
	The effective rate of depreciation was 2.26% in 2014, 2.28% in 2013, and 2.13% in 2012 on average utility plant, net of customers' advances and contributions.  Larger depreciation provisions resulting from allowable accelerated methods are deducted for tax purposes.
	Cash and Cash Equivalents
	For the purposes of the statements of cash flows, the Company considers all highly liquid debt instruments purchased with a maturity of three months or less to be cash equivalents except for those instruments earmarked to fund construction expenditures or repay long-term debt.
	The Company periodically maintains cash balances in major financial institutions in excess of the federally insured limit by the Federal Deposit Insurance Corporation (FDIC). The Company has not experienced any losses and believes it is not exposed to any significant credit risk on cash and cash equivalents.
	Restricted Cash
	The Company serves as the custodian for an escrow account that was used to rehabilitate a neighborhood within the service territory of the Company. The deposits made by various community organizations have been classified as restricted cash on the balance sheet of the Company. The project is nearing completion and the remaining cash will be disbursed in 2015.
	In 2012, the Company had a compensating balance requirement for one of its lines of credit which was recorded as Restricted Cash – compensating balance. This requirement was removed in 2013.
	Accounts Receivable
	Accounts receivable are stated at outstanding balances, less a reserve for doubtful accounts. The reserve for doubtful accounts is established through provisions charged against income. Accounts deemed to be uncollectible are charged against the reserve and subsequent recoveries, if any, are credited to the reserve. The reserve for doubtful accounts is maintained at a level considered adequate to provide for losses that can be reasonably anticipated. Management's periodic evaluation of the adequacy of the reserve is based on past experience, agings of the receivables, adverse situations that may affect a customer's ability to pay, current economic conditions, and other relevant factors. This evaluation is inherently subjective. Unpaid balances remaining after the stated payment terms are considered past due.
	Revenue Recognition
	Operating revenues include amounts billed to water customers on a cycle basis and unbilled amounts based on actual and estimated usage from the latest meter reading to the end of the accounting period. Operating revenues also include amounts billed to wastewater customers as either a flat monthly fee or a metered rate based on water consumption. The metered wastewater revenue includes actual and estimated usage from the latest meter reading to the end of the accounting period.
	Materials and Supplies Inventories
	Materials and supplies inventories are stated at cost.  Costs are determined using the average cost method.
	Deferred Debt Expense
	Deferred debt expense is amortized on a straight-line basis over the term of the related debt.
	Notes Receivable
	Notes receivable are recorded at cost and represent amounts due from various municipalities for construction of water mains in their particular municipality. Management, considering current information and events regarding the borrowers' ability to repay their obligations, considers a note to be impaired when it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the note agreement. When a note is considered to be impaired, the carrying value of the note is written down. The amount of the impairment is measured based on the present value of expected future cash flows discounted at the note's effective interest rate.
	Regulatory Assets and Liabilities
	The Company is subject to the provisions of generally accepted accounting principles regarding rate-regulated entities. The accounting standards provide for the recognition of regulatory assets and liabilities as allowed by regulators for costs or credits that are reflected in current customer rates or are considered probable of being included in future rates. The regulatory assets or liabilities are then relieved as the cost or credit is reflected in rates. Regulatory assets represent costs that are expected to be fully recovered from customers in future rates while regulatory liabilities represent amounts that are expected to be refunded to customers in future rates. These deferred costs have been excluded from the Company's rate base and, therefore, no return is being earned on the unamortized balances.
	Regulatory assets and liabilities are comprised of the following:
			December 31,				Remaining Recovery
			2014		2013		Periods
	Assets
	Income taxes		$	15,800	$	5,653	Various
	Postretirement benefits			12,493		7,136	5 – 10 years
	Unrealized swap losses			2,561		1,611	1 – 15 years
	Utility plant retirement costs			1,561		1,408	5 years
	Service life study expenses			5		7	3 years
	Rate case filing expenses			194		308	2 years
				32,614		16,123
	Liabilities
	IRS TPR catch-up deduction			4,314		-	Not yet known
	Income taxes			806		809	1 – 50 years
			$	5,120	$	809
	The regulatory asset for income taxes include (a) deferred state income taxes related primarily to differences between book and tax depreciation expense, (b) deferred income taxes related to the differences that arise between specific asset improvement costs capitalized for book purposes and deducted as a repair expense for tax purposes, and (c) deferred income taxes associated with the gross-up of revenues related to the differences. These assets are recognized for ratemaking purposes on a cash or flow-through basis and will be recovered in rates as they reverse.
	Postretirement benefits include (a) deferred pension expense in excess of contributions made to the plans, and (b) the underfunded status of the pension plans.  The underfunded status represents the excess of the projected benefit obligation over the fair market value of the assets. Both are expected to be recovered in future years as additional contributions are made or market conditions improve. The recovery period is dependent on contributions made to the plans, plan asset performance and the discount rate used to value the obligations.  The period is estimated at between 5 and 10 years.
	The Company uses regulatory accounting treatment to defer the mark-to-market unrealized gains and losses on its interest rate swap to reflect that the gain or loss is included in the ratemaking formula when the transaction actually settles. The value of the swap as of the balance sheet date is recorded as part of other deferred credits.  Realized gains or losses on the swap will be recorded as interest expense in the statement of income over its remaining life of 15 years.
	Utility plant retirement costs, including cost of removal, represents costs already incurred which are expected to be recovered over a five-year period in rates, through depreciation expense.  Service life study and rate case filing expenses are deferred and amortized over their remaining lives of three and two years, respectively.
	The regulatory liability for the Internal Revenue Service, or IRS, tangible property regulations, or TPR, catch-up deduction represents the tax benefits anticipated to be realized on the Company's 2014 income tax return for qualifying capital expenditures made prior to 2014. The Company will seek approval from the PPUC to amortize this amount in the future.
	The regulatory liability for income taxes relates mainly to deferred investment tax credits, and additionally to deferred taxes related to postretirement death benefits and bad debts.  These liabilities will be given back to customers in rates as tax deductions occur over the next 1-50 years.
	Regulatory liabilities are part of other accrued expenses and other deferred credits on the balance sheets.
	Other Assets
	Other assets consist mainly of the cash value of life insurance policies held as an investment by the Company for reimbursement of costs and benefits associated with its supplemental retirement and deferred compensation programs.
	Customers' Advances for Construction
Customer advances are cash payments from developers, municipalities, customers or builders for construction of utility plant, and are refundable upon completion of construction, as operating revenues are earned. If the Company loaned funds for construction to the customer, the refund amount is credited to the note receivable rather than paid out in cash. After all refunds to which the customer is entitled are made, any remaining balance is transferred to contributions in aid of construction. From 1986 to 1996 when customer advances were taxable income to the Company, additional funds were collected from customers to cover the taxes. Those funds were recorded as a liability within Customer Advances and are being amortized as deferred income over the tax life of the underlying assets.
Contributions in Aid of Construction
Contributions in Aid of Construction is composed of (i) direct, non-refundable contributions from developers, customers or builders for construction of water infrastructure and (ii) customer advances that have become non-refundable. Contributions in aid of construction are deducted from the Company's rate base, and therefore, no return is earned on property financed with contributions. The PPUC requires that contributions received remain on the Company's balance sheet indefinitely as a long-term liability.
Interest Rate Swap Agreement
The Company is exposed to certain risks relating to its ongoing business operations. The primary risk managed by using derivative instruments is interest rate risk. The Company utilizes an interest rate swap agreement to convert its variable-rate debt to a fixed rate. The Company has designated the interest rate swap agreement as a cash flow hedge. Interest rate swaps are contracts in which a series of interest rate cash flows are exchanged over a prescribed period. The notional amount on which the interest payments are based is not exchanged. The interest rate swap agreement is classified as a financial derivative used for non-trading activities.
The accounting standards regarding accounting for derivatives and hedging activities requires companies to recognize all derivative instruments as either assets or liabilities at fair value on the balance sheet. In accordance with the standards, the interest rate swap is recorded on the balance sheet in other deferred credits at fair value.
The Company uses regulatory accounting treatment rather than hedge accounting to defer the unrealized gains and losses on its interest rate swap. Instead of the effective portion being recorded as other comprehensive income and the ineffective portion being recognized in earnings, the entire unrealized swap value is recorded as a regulatory asset. Based on current ratemaking treatment, the Company expects the gains and losses to be recognized in rates and in interest expense as the swap settlements occur.  Swap settlements are recorded in the income statement with the hedged item as interest expense.  During the year ended December 31, 2014, $368 was reclassified from regulatory assets to interest expense as a result of swap settlements.  The overall swap result was a (gain) loss of $1,318 in 2014, $(830) in 2013, and $358 in 2012.  During the twelve months ending December 31, 2015, the Company expects to reclassify $353 (before tax) from regulatory assets to interest expense.
The interest rate swap will expire on October 1, 2029.
Income Taxes
Certain income and expense items are accounted for in different time periods for financial reporting than for income tax reporting purposes.
Deferred income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and tax credit carryforwards.  Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. To the extent such income taxes increase or decrease future rates, an offsetting regulatory asset or liability has been recorded.
Investment tax credits have been deferred and are being amortized to income over the average estimated service lives of the related assets.  As of December 31, 2014 and 2013, deferred investment tax credits amounted to $734 and $773, respectively.
In anticipation of filing for a change in accounting method under the IRS TPR when the 2014 income tax return is filed, the Company adjusted its income tax provision for the effects of this change during the fourth quarter of 2014. Under the change in accounting method, the Company is permitted to deduct the costs of certain asset improvements that were previously being capitalized and depreciated for tax purposes as an expense on its income tax return. The Company is permitted to make this deduction for prior years (the "catch-up deduction") and each year going forward, beginning with 2014 (the "ongoing deduction"). The ongoing deduction resulted in a reduction in the effective income tax rate, a net reduction in income tax expense, and reduced the amount of income taxes currently payable. The catch-up deduction resulted in a decrease in current income taxes payable and an increase to regulatory liabilities. The Company will seek approval from the PPUC in the next few years to amortize the amount recorded as a regulatory liability. Both the ongoing and catch-up deductions resulted in increases to deferred tax liabilities and regulatory assets representing the appropriate book and tax basis difference on capital additions.
Allowance for Funds Used During Construction
Allowance for funds used during construction (AFUDC) represents the estimated cost of funds used for construction purposes during the period of construction.  These costs are reflected as non-cash income during the construction period and as an addition to the cost of plant constructed. AFUDC includes the net cost of borrowed funds and a rate of return on other funds. The PPUC approved rate of 10.04% was applied for 2014, 2013 and 2012.  AFUDC is recovered through water and wastewater rates as utility plant is depreciated.
Use of Estimates in the Preparation of Financial Statements
The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Impact of Recent Accounting Pronouncements
In August 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-15, Disclosure of Uncertainties About an Entity's Ability to Continue as a Going Concern, which provides guidance on determining when and how reporting entities must disclose going-concern uncertainties in their financial statements. The new standard requires management to perform interim and annual assessments of an entity's ability to continue as a going concern within one year of the date of issuance of the entity's financial statements.  Further, an entity must provide certain disclosures if there is substantial doubt about the entity's ability to continue as a going concern.  The ASU is effective for fiscal years ending on or after December 15, 2016 and interim periods thereafter. The Company will comply with these assessments, but does not expect the adoption of this accounting standard to have any impact on its financial statements.
In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers.  This ASU supersedes the revenue recognition requirements in Accounting Standards Codification 605—Revenue Recognition and most industry-specific guidance throughout the Codification. The standard requires that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. This ASU is effective for fiscal years beginning after December 15, 2016, and for interim periods within those fiscal years. The Company is in the process of assessing the impact of the adoption of ASU 2014-09 on its financial position, results of operations and cash flows.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2014
Acquisitions
Acquisitions	2	Acquisitions
	On July 31, 2012, the Company completed the acquisition of the wastewater facilities of the Asbury Pointe Water and Sewer Company, in York County, Pennsylvania.  The Company began operating the existing collection and treatment facilities on August 1, 2012.  The acquisition resulted in the addition of approximately 240 wastewater customers with purchase price and acquisition costs of approximately $359, which is less than the depreciated original cost of the assets.  The Company recorded a negative acquisition adjustment of approximately $367 as of December 31, 2012.  During the third quarter of 2013, the Company received a refund of approximately $1 for certain acquisition expenditures which resulted in an increase of the negative acquisition adjustment to $368.  The Company has received approval from the PPUC to amortize the negative acquisition adjustment over the remaining life of the acquired assets beginning in 2014.
	On August 16, 2012, the Company completed the acquisition and began operating the water system of York Starview, LP in York County, Pennsylvania.  The Company acquired and is using York Starview's distribution facilities through an interconnection with its current distribution system.  The acquisition resulted in the addition of approximately 240 new water customers with purchase price and acquisition costs of approximately $131, which is more than the depreciated original costs of the assets.  The Company recorded a positive acquisition adjustment of approximately $36.  The Company has received approval from the PPUC to amortize the positive acquisition adjustment over the remaining life of the acquired assets beginning in 2014.
	On October 12, 2012, the Company completed the acquisition of the water system of Section A Water Corporation in Adams County, Pennsylvania.  The Company began operating the existing system as a satellite location on October 15, 2012.  The acquisition resulted in the addition of approximately 100 new water customers at a purchase price including acquisition costs of approximately $171.  The Company recorded a positive acquisition adjustment of approximately $35. The Company has received approval from the PPUC to amortize the positive acquisition adjustment over the remaining life of the acquired assets beginning in 2014.
	On March 7, 2013, the Company completed the acquisition of the Windy Brae Mobile Home Park water assets of Barkas, Inc. in York County, Pennsylvania.  The Company began operating the existing system through an interconnection with its current distribution system on March 11, 2013.  The acquisition resulted in the addition of approximately 135 new water customers with purchase price and acquisition costs of approximately $29, which is less than the depreciated original cost of the assets.  The Company recorded a negative acquisition adjustment of approximately $45 and will seek approval from the PPUC to amortize the negative acquisition adjustment over the remaining life of the acquired assets.
	On February 7, 2014, the Company completed the acquisition of the wastewater facilities of East Prospect Borough Authority in York County, Pennsylvania. The Company began operating the existing collection and treatment facilities on February 8, 2014. The acquisition resulted in the addition of approximately 400 wastewater customers with purchase price and acquisition costs of approximately $281, which is less than the depreciated original cost of the assets. The Company recorded a negative acquisition adjustment of approximately $667 and will seek approval from the PPUC to amortize the negative acquisition adjustment over the remaining life of the acquired assets.
	On May 30, 2014, the Company completed the acquisition of the water assets of Forest Lakes Water Association in York County, Pennsylvania. The Company began operating the existing system through an interconnection with its current distribution system on June 2, 2014. The acquisition resulted in the addition of approximately 70 new water customers with purchase price and acquisition costs of approximately $18, which is less than the depreciated original cost of the assets. The Company recorded a negative acquisition adjustment of approximately $9 and will seek approval from the PPUC to amortize the negative acquisition adjustment over the remaining life of the acquired assets.
	On November 20, 2014, the Company completed the acquisition of the water assets of Lincoln Estates Mobile Home Park in Adams County, Pennsylvania. The Company began operating the existing system as a satellite location on November 24, 2014. The acquisition resulted in the addition of approximately 200 new water customers with purchase price and acquisition costs of approximately $70.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes
Income Taxes	3	Income Taxes
	The provisions for income taxes consist of:
			2014			2013			2012
	Federal current		$	96		$	2,720		$	2,100
	State current			28			1,153			1,195
	Federal deferred			3,757			1,907			2,371
	State deferred			1,035			71			(21	)
	Federal investment tax credit, net of current utilization			(39	)		(39	)		(39	)
	Total income taxes		$	4,877		$	5,812		$	5,606
	A reconciliation of the statutory Federal tax provision (34%) to the total provision follows:
			2014			2013			2012
	Statutory Federal tax provision		$	5,563		$	5,258		$	5,069
	State income taxes, net of Federal benefit			702			808			775
	IRS TPR ongoing deduction			(1,342	)		-			-
	Tax-exempt interest			(37	)		(34	)		(33	)
	Amortization of investment tax credit			(39	)		(39	)		(39	)
	Cash value of life insurance			15			(32	)		(27	)
	Domestic production deduction			-			(154	)		(140	)
	Other, net			15			5			1
	Total income taxes		$	4,877		$	5,812		$	5,606
	In anticipation of filing for a change in accounting method under the IRS TPR when the 2014 income tax return is filed, the Company adjusted its income tax provision for the effects of this change during the fourth quarter of 2014. Under the change in accounting method, the Company is permitted to deduct the costs of certain asset improvements that were previously being capitalized and depreciated for tax purposes, as an expense on its income tax return. The Company is permitted to make this deduction for prior years (the "catch-up deduction") and each year going forward, beginning with 2014 (the "ongoing deduction"). As a result of the ongoing deduction, the net 2014 income tax benefits of $1,342 reduced income tax expense and flowed-through to net income in the fourth quarter of 2014, and the income tax benefits of $4,314 for the catch-up deduction have been deferred as a regulatory liability as of December 31, 2014. The ongoing deduction resulted in a reduction in the effective income tax rate, a net reduction in income tax expense, and reduced the amount of income taxes currently payable. The catch-up deduction resulted in a decrease in current income taxes payable and an increase to regulatory liabilities.  The Company will seek approval from the PPUC in the next few years, to amortize the amount recorded as a regulatory liability. Both the ongoing and catch-up deductions resulted in increases to deferred tax liabilities and regulatory assets representing the appropriate book and tax basis difference on capital additions.
	The tax effects of temporary differences between book and tax balances that give rise to significant portions of the deferred tax assets and deferred tax liabilities as of December 31, 2014 and 2013 are summarized in the following table:
			2014			2013
	Deferred tax assets:
	Reserve for doubtful accounts		$	132		$	130
	Compensated absences			209			193
	Deferred compensation			1,452			1,265
	Customers' advances and contributions			8			20
	Deferred taxes associated with the gross-up of revenues necessary to return, in rates, the effect of temporary differences			123			114
	Pensions			4,185			2,010
	Tax loss carryover			836			-
	Contribution carryover			183			-
	Other costs deducted for book, not for tax			49			37
	Total deferred tax assets			7,177			3,769
	Deferred tax liabilities:
	Accelerated depreciation			34,000			32,260
	Basis differences from IRS TPR			5,917			-
	Investment tax credit			436			459
	Deferred taxes associated with the gross-up of revenues necessary to recover, in rates, the effect of temporary differences			6,210			2,080
	Tax effect of pension regulatory asset			5,071			2,897
	Other costs deducted for tax, not for book			509			448
	Total deferred tax liabilities			52,143			38,144
	Net deferred tax liability		$	44,966		$	34,375
	Reflected on balance sheets as:
	Current deferred tax asset		$	(1,058	)	$	(219	)
	Noncurrent deferred tax liability			46,024			34,594
	Net deferred tax liability		$	44,966		$	34,375
	The Company has a federal tax loss carryover of $1,887 and a state tax loss carryover of $2,956.  If not used, these carryovers will expire in 2034. The Company expects to be able to use the tax loss carryforwards in 2015. The Company has a contribution carryover of $451.  If not used, this carryover will expire in 2019.
	No valuation allowance is required for deferred tax assets as of December 31, 2014 and 2013.  In assessing the soundness of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. Based upon expected future taxable income and the current regulatory environment, management believes it is more likely than not that the Company will realize the benefits of these deductible differences.
	The Company determined that there were no uncertain tax positions meeting the recognition and measurement test of the accounting standards recorded in the years that remain open for review by taxing authorities, which are 2011 through 2013 for both federal and state income tax returns.  The Company has not yet filed tax returns for 2014, but has taken one new position in its 2014 income tax provision, the implementation of the IRS TPR previously detailed.
	The Company's policy is to recognize interest and penalties related to income tax matters in other expenses.  There were no interest or penalties for the years ended December 31, 2014, 2013, and 2012.

LongTerm_Debt_and_ShortTerm_Bo

Long-Term Debt and Short-Term Borrowings	12 Months Ended
	Dec. 31, 2014
Long-Term Debt and Short-Term Borrowings [Abstract]
Long-Term Debt and Short-Term Borrowings	4	Long-Term Debt and Short-Term Borrowings
	Long-term debt as of December 31, 2014 and 2013 is summarized in the following table:
			2014				2013
	4.05% Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series A, due 2016		$	2,350			$	2,350
	5.00% Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series A, due 2016			4,950				4,950
	10.17% Senior Notes, Series A, due 2019			6,000				6,000
	9.60% Senior Notes, Series B, due 2019			5,000				5,000
	1.00% Pennvest Loan, due 2019			205				248
	10.05% Senior Notes, Series C, due 2020			6,500				6,500
	8.43% Senior Notes, Series D, due 2022			7,500				7,500
	Variable Rate Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series 2008A, due 2029			12,000				12,000
	4.75% Industrial Development Authority Revenue Bonds, Series 2006, due 2036			10,500				10,500
	6.00% Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series 2008B, due 2038			-				14,880
	4.50 % Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Refunding Bonds, Series 2014, due 2038			14,880				-
	5.00% Monthly Senior Notes, Series 2010A, due 2040			15,000				15,000
	Total long-term debt			84,885				84,928
	Less current maturities			(43	)			(43	)
	Long-term portion		$	84,842			$	84,885
	Payments due by year:
	2015				2016				2017			2018			2019
		$	43			$	19,344			$	44		$	44		$	11,030
	The 6.00% Pennsylvania Economic Development Financing Authority, or PEDFA, Exempt Facilities Revenue Bonds, Series 2008B, contained both optional and special redemption provisions.  In 2014, no bonds were retired under these provisions.  In 2013, the Company retired $5 under these provisions.  These bonds were redeemed in 2014.
	The 4.05% and 5.00% PEDFA Exempt Facilities Revenue Bonds, Series A, contain optional redemption provisions that allow the Company to redeem all or a portion of the bonds on or after April 1, 2014.
	Payments due in 2016 include potential payments of $12,000 on the variable rate bonds (due 2029) which would only be payable if all of the bonds were tendered and could not be remarketed.  There is currently no such indication of this happening.
	Fixed Rate Long-Term Debt
	On April 25, 2014, the Pennsylvania Economic Development Financing Authority (the "PEDFA") issued $14,880 aggregate principal amount of PEDFA Exempt Facilities Revenue Refunding Bonds, Series 2014 (the "Series 2014 Bonds") for the Company's benefit pursuant to the terms of a trust indenture, dated as of April 1, 2014, between the PEDFA and Manufacturers and Traders Trust Company, as trustee. The PEDFA then loaned the proceeds of the offering of the Series 2014 Bonds to the Company pursuant to a loan agreement, dated as of April 1, 2014, between the Company and the PEDFA.  The loan bears interest at a rate of 4.50% payable semiannually.  The maturity date of the loan is November 1, 2038.  Amounts outstanding under the loan agreement are direct, unsecured and unsubordinated obligations of the Company.  The proceeds of the loan were used to redeem the 6.00% PEDFA Exempt Facilities Revenue Refunding Bonds, Series 2008B.  The refinancing will reduce interest expense and lower the overall effective debt rate going forward.
	The Series 2014 Bonds contain both optional and special redemption provisions. Under the optional provisions, the Company can redeem all or a portion of the bonds on or after May 1, 2019. Under the special provisions, representatives of deceased beneficial owners of the bonds have the right to request redemption prior to the stated maturity of all or part of their interest in the bonds beginning on or after May 1, 2014. The Company is not obligated to redeem any individual interest exceeding $25, or aggregate interest exceeding $300, in any annual period.  Currently, no bonds that met the special provisions have been tendered for redemption.
	Variable Rate Long-Term Debt
	On May 7, 2008, the PEDFA issued $12,000 aggregate principal amount of PEDFA Exempt Facilities Revenue Refunding Bonds, Series A of 2008 (the "Series A Bonds") for the Company's benefit pursuant to the terms of a trust indenture, dated as of May 1, 2008, between the PEDFA and Manufacturers and Traders Trust Company, as trustee.  The PEDFA then loaned the proceeds of the offering of the Series A Bonds to us pursuant to a loan agreement, dated as of May 1, 2008, between us and the PEDFA.  The loan agreement provides for a $12,000 loan with a maturity date of October 1, 2029.  Amounts outstanding under the loan agreement are the Company's direct general obligations.  The proceeds of the loan were used to redeem the PEDFA Exempt Facilities Revenue Bonds, Series B of 2004 (the "2004 Series B Bonds").  The 2004 Series B Bonds were redeemed because the bonds were tendered and could not be remarketed due to the downgrade of the bond insurer's credit rating.
	Borrowings under the loan agreement bear interest at a variable rate as determined by PNC Capital Markets, as remarketing agent, on a periodic basis elected by us. The Company has currently elected that the interest rate be determined on a weekly basis. The remarketing agent determines the interest rate based on then current market conditions in order to determine the lowest interest rate which would cause the Series A Bonds to have a market value equal to the principal amount thereof plus accrued interest thereon.  The variable interest rate under the loan agreement averaged 0.07% in 2014 and 0.13%  in 2013.  As of December 31, 2014 and 2013, the interest rate was 0.05% and 0.09%, respectively.
	The holders of the $12,000 Series A Bonds may tender their bonds at any time.  When the bonds are tendered, they are subject to an annual remarketing agreement, pursuant to which a remarketing agent attempts to remarket the tendered bonds pursuant to the terms of the indenture. In order to keep variable interest rates down and to enhance the marketability of the Series A Bonds, the Company entered into a Reimbursement, Credit and Security Agreement with PNC Bank, National Association ("the Bank") dated as of May 1, 2008. This agreement provides for a direct pay letter of credit issued by the Bank to the trustee for the Series A Bonds. The Bank is responsible for providing the trustee with funds for the timely payment of the principal and interest on the Series A Bonds and for the purchase price of the Series A Bonds that have been tendered or deemed tendered for purchase and have not been remarketed. The Company's responsibility is to reimburse the Bank the same day as regular interest payments are made, and within fourteen months for the purchase price of tendered bonds that have not been remarketed. The reimbursement period for the principal is immediate at maturity, upon default by the Company, or if the Bank does not renew the Letter of Credit.  The current expiration date of the Letter of Credit is June 30, 2017.  It is reviewed annually for a potential extension of the expiration date.
	The Company may elect to have the Series A Bonds redeemed, in whole or in part, on any date that interest is payable for a redemption price equal to the principal amount thereof plus accrued interest to the date of redemption. The Series A Bonds are also subject to mandatory redemption for the same redemption price in the event that the Internal Revenue Service determines that the interest payable on the Series A Bonds is includable in gross income of the holders of the bonds for federal tax purposes.
	Interest Rate Swap Agreement
	In connection with the issuance of the PEDFA 2004 Series B Bonds, the Company entered into an interest rate swap agreement with a counterparty, in the notional principal amount of $12,000.  The Company elected to retain the swap agreement for the 2008 Series A Bonds. Interest rate swap agreements derive their value from underlying interest rates. These transactions involve both credit and market risk. The notional amounts are amounts on which calculations, payments, and the value of the derivative are based. Notional amounts do not represent direct credit exposure. Direct credit exposure is limited to the net difference between the calculated amounts to be received and paid, if any. Such difference, which represents the fair value of the swap, is reflected on the Company's balance sheet. See Note 10 for additional information regarding the fair value of the swap.
	The interest rate swap will terminate on the maturity date of the 2008 Series A Bonds (which is the same date as the maturity date of the loan under the loan agreement), unless sooner terminated pursuant to its terms. In the event the interest rate swap terminates prior to the maturity date of the 2008 Series A Bonds, either the Company or the swap counterparty may be required to make a termination payment to the other based on market conditions at such time. The Company is exposed to credit-related losses in the event of nonperformance by the counterparty. The Company controls the credit risk of its financial contracts through credit approvals, limits and monitoring procedures, and does not expect the counterparty to default on its obligations. Notwithstanding the terms of the swap agreement, the Company is ultimately obligated for all amounts due and payable under the loan agreement.
	The interest rate swap agreement contains provisions that require the Company to maintain a credit rating of at least BBB- with Standard & Poor's.  On April 11, 2014, Standard & Poor's affirmed the Company's credit rating at A-, with a stable outlook and adequate liquidity.  If the Company's rating were to fall below this rating, it would be in violation of these provisions, and the counterparty to the derivative could request immediate payment if the derivative was in a liability position.  The Company's interest rate swap was in a liability position as of December 31, 2014.  If a violation were triggered on December 31, 2014, the Company would have been required to pay the counterparty approximately $2,667.
	The Company's interest rate swap agreement provides that it pay the counterparty a fixed interest rate of 3.16% on the notional amount of $12,000. In exchange, the counterparty pays the Company a floating interest rate (based on 59% of the U.S. Dollar one-month LIBOR rate) on the notional amount.  The floating interest rate paid to the Company is intended, over the term of the swap, to approximate the variable interest rate on the loan agreement and the interest rate paid to bondholders, thereby managing its exposure to fluctuations in prevailing interest rates.  The Company's net payment rate on the swap averaged 3.07% in 2014 and 3.05% in 2013.
	As of December 31, 2014, there was a negative spread of 5 basis points between the variable rate paid to bondholders and the variable rate received from the swap counterparty, which equated to an overall effective rate of 3.11% (including variable interest and swap payments).  As of December 31, 2013, there was a negative spread of 1 basis point which equated to an overall effective rate of 3.15% (including variable interest and swap payments).
	Short-Term Borrowings
	As of December 31, 2014, the Company maintained unsecured lines of credit aggregating $29,000 with three banks.  The first line of credit, in the amount of $13,000, is a committed line of credit with a revolving 2-year maturity (currently May 2016), and carries an interest rate of LIBOR plus 1.20%.  The second line of credit, in the amount of $11,000, is a committed line of credit, which matures in May 2016 and carries an interest rate of LIBOR plus 1.25%.  This line of credit had a compensating balance requirement of $500 which was eliminated in 2013.  The third line of credit, in the amount of $5,000, is a committed line of credit, which matures in June 2015 and carries an interest rate of LIBOR plus 1.50%.  The Company had no outstanding borrowings under any of its lines of credit as of December 31, 2014 and 2013.
	Debt Covenants and Restrictions
	The terms of the debt agreements carry certain covenants and limit in some cases the Company's ability to borrow additional funds, to prepay its borrowings and include certain restrictions with respect to declaration and payment of cash dividends and acquisition of the Company's stock.  Under the terms of the most restrictive agreements, the Company cannot borrow in excess of 60% of its utility plant, and cumulative payments for dividends and acquisition of stock since December 31, 1982 may not exceed $1,500 plus net income since that date.  As of December 31, 2014, none of the earnings retained in the business are restricted under these provisions.  The Company's Pennvest Loan is secured by $800 of receivables.  Other than this loan, the Company's debt is unsecured.
	The Company's lines of credit require it to maintain a minimum equity to total capitalization ratio (defined as the sum of equity plus funded debt) and a minimum interest coverage ratio (defined as net income plus interest expense plus income tax expense divided by interest expense).  As of December 31, 2014, the Company was in compliance with these covenants.

Common_Stock_and_Earnings_Per_

Common Stock and Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Common Stock And Earnings Per Share [Abstract]
Common Stock and Earnings Per Share	5	Common Stock and Earnings Per Share
	Earnings per share are based upon the weighted average number of shares outstanding of 12,879,912 in 2014, 12,928,040 in 2013, and 12,847,160 in 2012.  The Company does not have dilutive securities outstanding.
	Under the employee stock purchase plan, all full-time employees who have been employed at least ninety consecutive days may purchase shares of the Company's common stock limited to 10% of gross compensation.  The purchase price is 95% of the fair market value (as defined).  Shares issued during 2014, 2013 and 2012 were 7,431, 6,711 and 7,776, respectively.  As of December 31, 2014, 88,128 authorized shares remain unissued under the plan.
	The Company has a Dividend Reinvestment and Direct Stock Purchase and Sale Plan, which is available to both current shareholders and the general public.  Certain restrictions apply.  Purchases are made weekly at 100% of the stock's fair market value, as defined in the Prospectus contained in Amendment No. 1 to Securities and Exchange Commission Form S-3, filed by the Company on June 26, 2008.
	Under the optional dividend reinvestment portion of the plan, holders of the Company's common stock may purchase additional shares instead of receiving cash dividends.  The purchase price is 95% of the fair market value (as defined).
	Shares issued under the 2008 Dividend Reinvestment and Direct Stock Purchase and Sale Plan, during 2013 and 2012 were 112,163 and 119,186, respectively.  No shares were issued under this Plan after October 30, 2013.
	On October 1, 2013, the Company filed a Registration Statement on Form S-3 with the SEC to authorize 500,000 shares to be issued under the new Prospectus for the Dividend Reinvestment and Direct Stock Purchase and Sale Plan.  Other provisions of the plan were left substantially unchanged.  The Registration Statement was declared effective by the SEC on October 31, 2013.  Shares issued in 2014 and 2013 under the new Prospectus were 126,379 and 36,188, respectively.  As of December 31, 2014, 337,433 authorized shares remain unissued under the plan.
	On March 11, 2013, the Board of Directors authorized a share repurchase program granting the Company authority to repurchase up to 1,200,000 shares of the Company's common stock from time to time.  Under the stock repurchase program, the Company may repurchase shares in the open market or through privately negotiated transactions.  The Company may suspend or discontinue the repurchase program at any time.  During 2014 and 2013, the Company repurchased and retired 282,570 and 94,414 shares, respectively.  As of December 31, 2014, 823,016 shares remain available for repurchase.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2014
Employee Benefit Plans
Employee Benefit Plans	6	Employee Benefit Plans
	Pensions
	The Company maintains a general and administrative and a union-represented defined benefit pension plan covering all of its employees hired prior to May 1, 2010. Employees hired after May 1, 2010 are eligible for an enhanced 401(k) plan rather than a defined benefit plan. The benefits under the defined benefit plans are based upon years of service and compensation near retirement. The Company amended its defined benefit pension plans in 2014, generally limiting the years of eligible service under the plans to 30 years. The Company's funding policy is to contribute annually the amount permitted by the PPUC to be collected from customers in rates, but in no case less than the minimum Employee Retirement Income Security Act (ERISA) required contribution.
	The following table sets forth the plans' funded status as of December 31, 2014 and 2013.  The measurement of assets and obligations of the plans is as of December 31, 2014 and 2013.
	Obligations and Funded Status		2014				2013
	At December 31
	Change in Benefit Obligation
	Pension benefit obligation beginning of year		$	32,054			$	34,726
	Service cost			952				1,188
	Interest cost			1,444				1,280
	Actuarial (gain) loss			7,762				(4,074	)
	Plan amendments			(210	)			-
	Benefit payments			(1,118	)			(1,066	)
	Pension benefit obligation end of year			40,884				32,054
	Change in Plan Assets
	Fair value of plan assets beginning of year			27,102				22,666
	Actual return on plan assets			2,409				3,911
	Employer contributions			2,182				1,593
	Benefits paid			(1,118	)			(1,068	)
	Fair value of plan assets end of year			30,575				27,102
	Funded Status of Plans at End of Year		$	(10,309	)		$	(4,952	)
	The accounting standards require that the funded status of defined benefit pension plans be fully recognized on the balance sheet. They also call for the unrecognized actuarial gain or loss, the unrecognized prior service cost and the unrecognized transition costs to be adjustments to shareholders' equity (accumulated other comprehensive income). Due to a rate order granted by the PPUC, the Company is permitted under the accounting standards to defer the charges to accumulated other comprehensive income as a regulatory asset. Management believes these costs will be recovered in future rates charged to customers. The liability for the funded status of the Company's pension plans is recorded in "Deferred employee benefits" on its balance sheet.
	In 2014, the actuarial loss grew substantially due to the 85 basis point decline in the discount rate, and a change in mortality tables to the RP-2014 (White Collar and Blue Collar) which increased the life expectancy of plan participants.  The Company uses the corridor method to amortize actuarial gains and losses.  Gains and losses over 10% of the greater of pension benefit obligation or the market value of assets are amortized over the average future service of plan participants expected to receive benefits.
	Changes in plan assets and benefit obligations recognized in regulatory assets are as follows:
			2014				2013
	Net (gain) loss arising during the period		$	7,339			$	(6,339	)
	Recognized net actuarial loss			(126	)			(698	)
	Recognized prior service cost			(197	)			(10	)
	Total changes in regulatory asset during the year		$	7,016			$	(7,047	)
	Amounts recognized in regulatory assets that have not yet been recognized as components of net periodic benefit cost consist of the following at December 31:
			2014				2013
	Net loss		$	11,978			$	4,765
	Prior service (credit) cost			(140	)			57
	Regulatory asset		$	11,838			$	4,822
	Components of Net Periodic Benefit Cost are as follows:
			2014				2013				2012
	Service cost		$	952			$	1,188			$	1,050
	Interest cost			1,444				1,280				1,288
	Expected return on plan assets			(1,986	)			(1,644	)			(1,441	)
	Amortization of loss			126				698				641
	Amortization of prior service (credit) cost			(13	)			10				17
	Rate-regulated adjustment			1,659				61				38
	Net periodic benefit cost		$	2,182			$	1,593			$	1,593
	The rate-regulated adjustment set forth above is required in order to reflect pension expense for the Company in accordance with the method used in establishing water rates. The Company is permitted by rate order of the PPUC to expense pension costs to the extent of contributions and defer the remaining expense to regulatory assets to be collected in rates at a later date as additional contributions are made.  During 2014, the deferral decreased $1,659.
	The estimated costs for the defined benefit pension plans relating to the December 31, 2014 balance sheet that will be amortized from regulatory assets into net periodic benefit cost over the next fiscal year are as follows:
	Net loss		$	690
	Net prior service credit			(13	)
			$	677
	The Company plans to contribute $2,300 to the plans in 2015.
	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid in each of the next five years and the subsequent five years in the aggregate:
	2015				2016				2017				2018				2019					2020-2024
		$	1,544			$	1,584			$	1,576			$	1,727			$	1,861		$	10,278
	The following tables show the projected benefit obligation, the accumulated benefit obligation and the fair value of plan assets as of December 31:
			2014				2013
	Projected benefit obligation		$	40,884			$	32,054
	Fair value of plan assets			30,575				27,102
			2014				2013
	Accumulated benefit obligation		$	37,500			$	29,279
	Fair value of plan assets			30,575				27,102
	Weighted-average assumptions used to determine benefit obligations at December 31:
			2014				2013
	Discount rate			3.8	%			4.65	%
	Rate of compensation increase			3	%			3	%
	Weighted-average assumptions used to determine net periodic benefit cost for years ended December 31:
		2014				2013				2012
Discount rate			4.65	%			3.75	%			4.25	%
Expected long-term return on plan assets			7	%			7	%			7	%
Rate of compensation increase			3	%			3	%			3	%
The selected long-term rate of return on plan assets was primarily based on the asset allocation of the plan's assets (approximately 50% to 70% equity securities and 30% to 50% fixed income securities).  Analysis of the historic returns of these asset classes and projections of expected future returns were considered in setting the long-term rate of return.
The investment objective of the Company's defined benefit pension plans is that of Growth and Income.  The weighted-average target asset allocations are 50% to 70% equity securities, 30% to 50% fixed income securities, and 0% to 10% reserves (cash and cash equivalents).  Within the equity category, the Company's target allocation is approximately 60-95% large cap, 0-25% mid cap, 0-10% small cap, 0-25% International Developed Nations, and 0-10% International Emerging Nations.  Within the fixed income category, its target allocation is approximately 15-55% U.S. Treasuries, 0–22% Federal Agency securities, 0-40% corporate bonds, 15-55% mortgage-backed securities, 0-20% international, and 0-20% high yield bonds.  The Company's investment performance objectives over a three to five year period are to exceed the annual rate of inflation as measured by the Consumer Price Index by 3%, and to exceed the annualized total return of specified benchmarks applicable to the funds within the asset categories.
Further guidelines within equity securities include: (1) holdings in any one company cannot exceed 5% of the portfolio; (2) a minimum of 20 individual stocks must be included in the domestic stock portfolio; (3) a minimum of 30 individual stocks must be included in the international stock portfolio; (4) equity holdings in any one industry cannot exceed 20-25% of the portfolio; and (5) only U.S.-denominated currency securities are permitted.
Further guidelines for fixed income securities include: (1) fixed income holdings in a single issuer are limited to 5% of the portfolio; (2) acceptable investments include money market securities, U.S. Government and its agencies and sponsored entities' securities, mortgage-backed and asset-backed securities, corporate securities and mutual funds offering high yield bond portfolios; (3) purchases must be limited to investment grade or higher; (4) non-U.S. dollar denominated securities are not permissible; and (5) high risk derivatives are prohibited.
The fair values of the Company's pension plan assets at December 31, 2014 and 2013 by asset category and fair value hierarchy level are as follows.  The majority of the valuations are based on quoted prices on active markets (Level 1), with the remaining valuations based on broker/dealer quotes, active market makers, models, and yield curves (Level 2).
		Total Fair Value								Quoted Prices in Active Markets for Identical Assets (Level 1)								Significant Other Observable Inputs
																		(Level 2)
Asset Category		2014				2013				2014				2013				2014			2013
Cash and Money Market Funds (a)		$	1,064			$	621			$	1,064			$	621			$	-		$	-
Equity Securities:
Common Equity Securities (b)			3,031				5,136				3,031				5,136				-			-
Equity Mutual Funds (c)			16,380				13,907				16,380				13,907				-			-
Fixed Income Securities:
U.S. Treasury Obligations			831				815				-				-				831			815
Corporate and Foreign Bonds (d)			1,620				398				-				-				1,620			398
Fixed Income Mutual Funds (e)			7,649				6,225				7,649				6,225				-			-
Total Plan Assets		$	30,575			$	27,102			$	28,124			$	25,889			$	2,451		$	1,213
	(a)	The portfolios are designed to keep approximately three months of distributions in immediately available funds.  The Company was more heavily-weighted in cash as of December 31, 2014 some as a precaution, and some due to investments made but not settled prior to year end.
	(b)	This category includes investments in U.S. common stocks and foreign stocks trading in the U.S. widely distributed among consumer discretionary, consumer staples, healthcare, information technology, financial services, materials, industrials, energy and utilities. The individual stocks are primarily large cap stocks which track with the S&P 500 with the exception of $447 (1.5% of total plan assets) which is invested in York Water Company common stock.
	(c)	This category currently includes a majority of investments in closed-end mutual funds as well as domestic equity mutual funds and international mutual funds which give the portfolio exposure to mid and large cap index funds as well as international diversified index funds.
	(d)	This category currently includes only U.S. corporate bonds and notes widely distributed among consumer discretionary, consumer staples, healthcare, information technology, financial services, energy and utilities.
	(e)	This category includes fixed income investments in mutual funds which include government, corporate and mortgage securities of both the U.S. and other countries. The mortgage-backed securities and non-U.S. corporate and sovereign investments add further diversity to the fixed income portion of the portfolio.
Defined Contribution Plan
The Company has a savings plan pursuant to the provisions of section 401(k) of the Internal Revenue Code.  For employees hired before May 1, 2010, this plan provides for elective employee contributions of up to 15% of compensation and Company matching contributions of 100% of the participant's contribution, up to a maximum annual Company contribution of $2.8 for each employee.
Employees hired after May 1, 2010 are entitled to an enhanced feature of the plan.  This feature provides for elective employee contributions of up to 15% of compensation and Company matching contributions of 100% of the participant's contribution, up to a maximum of 4% of the employee's compensation.  In addition, the Company will make an annual contribution of $1.2 to each employee's account whether or not they defer their own compensation.  Employees eligible for this enhanced 401(k) plan feature are not eligible for the defined benefit plans.  As of December 31, 2014, sixteen employees were participating in the enhanced feature of the plan.  The Company's contributions to both portions of the plan amounted to $239 in 2014, $222 in 2013, and $244 in 2012.
Deferred Compensation
The Company has non-qualified deferred compensation and supplemental retirement agreements with certain members of management. The future commitments under these arrangements are offset by corporate-owned life insurance policies.  At December 31, 2014 and 2013, the present value of the future obligations was approximately $3,576 and $3,115, respectively.  The insurance policies included in other assets had a total cash value of approximately $3,567 and $3,591, respectively, at December 31, 2014 and 2013.  The Company's net (income) expenses under the plans amounted to $658 in 2014, $(91) in 2013 and $358 in 2012.
Other
The Company has a retiree life insurance program which pays the beneficiary of a retiree $2 upon the retiree's death.  At December 31, 2014 and 2013, the present value of the future obligations was approximately $110 and $91, respectively.  There is no trust or insurance covering this future liability, instead the Company will pay these benefits out of its general assets.  The Company's net (income) expenses under the plan amounted to $25 in 2014, $(14) in 2013 and $15 in 2012.

Rate_Increases

Rate Increases	12 Months Ended
	Dec. 31, 2014
Rate Increases [Abstract]
Rate Increases	7	Rate Increases
	From time to time, the Company files applications for rate increases with the PPUC and is granted rate relief as a result of such requests.  The most recent rate request was filed by the Company on May 29, 2013 and sought an increase in rates designed to produce additional annual water revenues of $7,116 and additional annual wastewater revenues of $28.  Effective February 28, 2014, the PPUC authorized an increase in water rates designed to produce approximately $4,972 in additional annual revenues, and an increase in wastewater rates for the Asbury Pointe subdivision to produce approximately $28 in additional annual revenues.
	The PPUC permits water utilities to collect a distribution system improvement charge (DSIC).  The DSIC allows the Company to add a charge to customers' bills for qualified replacement costs of certain infrastructure without submitting a rate filing.  This surcharge mechanism typically adjusts periodically based on additional qualified capital expenditures completed or anticipated in a future period.  The DSIC is capped at 5% of base rates, and is reset to zero when new base rates that reflect the costs of those additions become effective or when a utility's earnings exceed a regulatory benchmark.  The surcharge reset to zero when the new base rates took effect on February 28, 2014.  The DSIC provided revenues in 2014, 2013 and 2012 of $283, $1,445 and $583, respectively.  The DSIC is subject to audit by the PPUC.

Notes_Receivable_and_Customers

Notes Receivable and Customers' Advances for Construction	12 Months Ended
	Dec. 31, 2014
Notes Receivable and Customers' Advances for Construction [Abstract]
Notes Receivable and Customers' Advances for Construction	8	Notes Receivable and Customers' Advances for Construction
	The Company has agreements with three municipalities to extend water service into previously formed water districts.  The Company loaned funds to the municipalities to cover the costs related to the projects.  The municipalities concurrently advanced these funds back to the Company in the form of customers' advances for construction.  The municipalities are required by enacted ordinances to charge application fees and water revenue surcharges (fees) to customers connected to the system, which are remitted to the Company.  The note principal and the related customer advance are reduced periodically as operating revenues are earned by the Company from customers connected to the system and refunds of advances are made.  There is no due date for the notes or expiration date for the advances.
	The Company has recorded interest income of $107 in 2014, $101 in 2013 and $98 in 2012.  Interest rates on the notes outstanding at December 31, 2014 vary from 6.75% to 7.5%.
	Included in the accompanying balance sheets at December 31, 2014 and 2013 were the following amounts related to these projects.
			2014		2013
	Notes receivable, including interest		$	266	$	306
	Customers' advances for construction			626		928
	The Company has other customers' advances for construction totaling $10,086 and $10,708 at December 31, 2014 and 2013, respectively.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2014
Commitments [Abstract]
Commitments	9	Commitments
	Based on its capital budget, the Company anticipates construction and acquisition expenditures for 2015 and 2016 of approximately $14,100 and $15,800, respectively, exclusive of any acquisitions not yet approved. The Company plans to finance ongoing capital expenditures with internally-generated funds, borrowings against the Company's lines of credit, proceeds from the issuance of common stock under its dividend reinvestment and direct stock purchase and sale plan and ESPP, potential common stock or debt issues and customer advances.
	As of December 31, 2014, the Company employed 107 full time people, including 38 under union contract.  The current contract was ratified in March 2014 and expires on April 30, 2017.
	The Company is involved in certain legal and administrative proceedings before various courts and governmental agencies concerning water service and other matters.  The Company expects that the ultimate disposition of these proceedings will not have a material effect on the Company's financial position, results of operations and cash flows.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2014
Fair Value of Financial Instruments [Abstract]
Fair Value of Financial Instruments	10	Fair Value of Financial Instruments
	The accounting standards regarding fair value measurements establish a fair value hierarchy which indicates the extent to which inputs used in measuring fair value are observable in the market. Level 1 inputs include quoted prices for identical instruments and are the most observable. Level 2 inputs include quoted prices for similar assets and observable inputs such as interest rates, commodity rates and yield curves. Level 3 inputs are not observable in the market and include management's own judgments about the assumptions market participants would use in pricing the asset or liability.
	The Company has recorded its interest rate swap liability at fair value in accordance with the standards.  The liability is recorded under the caption "Other deferred credits" on the balance sheet.  The table below illustrates the fair value of the interest rate swap as of the end of the reporting period.
	Description	31-Dec-14	Fair Value Measurements
			at Reporting Date Using
			Significant Other Observable Inputs (Level 2)
	Interest Rate Swap	$2,592	$2,592
	Fair values are measured as the present value of all expected future cash flows based on the LIBOR-based swap yield curve as of the date of the valuation.  These inputs to this calculation are deemed to be Level 2 inputs.  The balance sheet carrying value reflects the Company's credit quality as of December 31, 2014.  The rate used in discounting all prospective cash flows anticipated to be made under this swap reflects a representation of the yield to maturity for 30-year debt on utilities rated A- as of December 31, 2014.  The use of the Company's credit quality resulted in a reduction in the swap liability of $75.  The fair value of the swap reflecting the Company's credit quality as of December 31, 2013 is shown in the table below.
	Description	31-Dec-13	Fair Value Measurements
			at Reporting Date Using
			Significant Other Observable Inputs (Level 2)
	Interest Rate Swap	$1,641	$1,641
	The carrying amount of current assets and liabilities that are considered financial instruments approximates fair value as of the dates presented.  The Company's long-term debt (including current maturities), with a carrying value of $84,885 at December 31, 2014, and $84,928 at December 31, 2013, had an estimated fair value of approximately $100,000 and $94,000 at December 31, 2014 and 2013, respectively.  The estimated fair value of debt was calculated using a discounted cash flow technique that incorporates a market interest yield curve with adjustments for duration and risk profile.  These inputs to this calculation are deemed to be Level 2 inputs.  The Company recognized its credit rating in determining the yield curve, and did not factor in third party credit enhancements including bond insurance on the 2004 PEDFA Series A and 2006 Industrial Development Authority issues, and the letter of credit on the 2008 PEDFA Series A issue.
	Customers' advances for construction and notes receivable have carrying values at December 31, 2014 of $10,712 and $266, respectively.  At December 31, 2013, customers' advances for construction and notes receivable had carrying values of $11,636 and $306, respectively.  The relative fair values of these amounts cannot be accurately estimated since the timing of future payment streams is dependent upon several factors, including new customer connections, customer consumption levels and future rate increases.

Taxes_Other_than_Income_Taxes

Taxes Other than Income Taxes	12 Months Ended
	Dec. 31, 2014
Taxes Other Than Income Taxes [Abstract]
Taxes Other than Income Taxes	11	Taxes Other than Income Taxes
	The following table provides the components of taxes other than income taxes:
			2014		2013		2012
	Regulatory Assessment		$	218	$	220	$	228
	Property			339		364		342
	Payroll, net of amounts capitalized			494		462		458
	Capital Stock			59		75		151
	Other			1		1		1
	Total taxes other than income taxes		$	1,111	$	1,122	$	1,180

Selected_Quarterly_Financial_D

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Data (Unaudited) [Abstract]
Selected Quarterly Financial Data (Unaudited)	12	Selected Quarterly Financial Data (Unaudited)
			First		Second		Third		Fourth		Year
	2014
	Operating revenues		$	10,571	$	11,768	$	12,062	$	11,499	$	45,900
	Operating income			4,758		5,800		6,092		5,427		22,077
	Net income*			2,111		2,757		3,065		3,551		11,484
	Basic earnings per share			0.16		0.22		0.23		0.28		0.89
	Dividends declared per share			0.1431		0.1431		0.1431		0.1495		0.5788
	* Fourth quarter net income includes a tax benefit of $1,342 for the full year 2014 due to the implementation of the IRS TPR.
	2013
	Operating revenues		$	10,069	$	10,737	$	10,912	$	10,665	$	42,383
	Operating income			4,773		5,301		5,367		5,320		20,761
	Net income			2,139		2,342		2,535		2,638		9,654
	Basic earnings per share			0.17		0.18		0.19		0.21		0.75
	Dividends declared per share			0.1383		0.1383		0.1383		0.1431		0.558

Schedule_II_Valuation_and_Qual

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Schedule II Valuation and Qualifying Accounts [Abstract]
Schedule II Valuation and Qualifying Accounts	SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS
	FOR THE THREE YEARS ENDED DECEMBER 31, 2014
					Additions
	Description	Balance at Beginning of Year			Charged to Cost and Expenses			Recoveries			Deductions			Balance at End of Year
	FOR THE YEAR ENDED DECEMBER 31, 2014
	Reserve for uncollectible accounts		$	320,000		$	322,499		$	44,071		$	361,570		$	325,000
	FOR THE YEAR ENDED DECEMBER 31, 2013
	Reserve for uncollectible accounts		$	305,000		$	290,886		$	36,369		$	312,255		$	320,000
	FOR THE YEAR ENDED DECEMBER 31, 2012
	Reserve for uncollectible accounts		$	333,681		$	302,032		$	46,789		$	377,502		$	305,000
	The Deductions column above represents write-offs of accounts receivable during the applicable year.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies
Nature of Operations	The primary business of The York Water Company is to impound, purify and distribute water.  The Company also operates two wastewater collection and treatment systems.  The Company operates within its franchised territory located in York and Adams Counties, Pennsylvania, and is subject to regulation by the Pennsylvania Public Utility Commission, or PPUC.
	The following summarizes the significant accounting policies employed by The York Water Company.
Utility Plant and Depreciation	Utility Plant and Depreciation
	The cost of additions includes contracted cost, direct labor and fringe benefits, materials, overhead and, for certain utility plant, allowance for funds used during construction. In accordance with regulatory accounting requirements, water and wastewater systems acquired are recorded at estimated original cost of utility plant when first devoted to utility service and the applicable depreciation is recorded to accumulated depreciation. The difference between the estimated original cost less applicable accumulated depreciation, and the purchase price is recorded as an acquisition adjustment within utility plant as permitted by the PPUC.  At December 31, 2014 and 2013, utility plant includes a net credit acquisition adjustment of $3,522 and $2,900, respectively.  For those amounts approved by the PPUC, the net acquisition adjustment is being amortized over the remaining life of the respective assets. Certain amounts are still awaiting approval from the PPUC before amortization will commence.  Amortization amounted to $54 in 2014, $50 in 2013, and $50 in 2012.
	Upon normal retirement of depreciable property, the estimated or actual cost of the asset is credited to the utility plant account, and such amounts, together with the cost of removal less salvage value, are charged to the reserve for depreciation. To the extent the Company recovers cost of removal or other retirement costs through rates after the retirement costs are incurred, a regulatory asset is reported. Gains or losses from abnormal retirements are reflected in income currently.
	The straight-line remaining life method is used to compute depreciation on utility plant cost, exclusive of land and land rights. Annual provisions for depreciation of transportation and mechanical equipment included in utility plant are computed on a straight-line basis over the estimated service lives. Such provisions are charged to clearing accounts and apportioned therefrom to operating expenses and other accounts in accordance with the Uniform System of Accounts as prescribed by the PPUC.
	The Company charges to maintenance expense the cost of repairs and replacements and renewals of minor items of property. Maintenance of transportation equipment is charged to clearing accounts and apportioned therefrom in a manner similar to depreciation. The cost of replacements, renewals and betterments of units of property is capitalized to the utility plant accounts.
	The following remaining lives are used for financial reporting purposes:
		December 31,				Approximate range
	Utility Plant Asset Category	2014		2013		of remaining lives
	Mains and accessories	$	164,627	$	157,113	10 – 84 years
	Services, meters and hydrants		63,479		61,206	19 – 55 years
	Operations structures, reservoirs and water tanks		43,654		42,692	11 – 41 years
	Pumping and treatment equipment		25,616		23,411	3 – 31 years
	Office, transportation and operating equipment		11,216		10,994	3 – 21 years
	Land and other non-depreciable assets		3,166		3,127	-
	Utility plant in service		311,758		298,543
	Construction work in progress		4,767		3,027	-
	Total Utility Plant	$	316,525	$	301,570
	The effective rate of depreciation was 2.26% in 2014, 2.28% in 2013, and 2.13% in 2012 on average utility plant, net of customers' advances and contributions.  Larger depreciation provisions resulting from allowable accelerated methods are deducted for tax purposes.
Cash and Cash Equivalents	Cash and Cash Equivalents
	For the purposes of the statements of cash flows, the Company considers all highly liquid debt instruments purchased with a maturity of three months or less to be cash equivalents except for those instruments earmarked to fund construction expenditures or repay long-term debt.
	The Company periodically maintains cash balances in major financial institutions in excess of the federally insured limit by the Federal Deposit Insurance Corporation (FDIC). The Company has not experienced any losses and believes it is not exposed to any significant credit risk on cash and cash equivalents.
Restricted Cash	Restricted Cash
	The Company serves as the custodian for an escrow account that was used to rehabilitate a neighborhood within the service territory of the Company. The deposits made by various community organizations have been classified as restricted cash on the balance sheet of the Company. The project is nearing completion and the remaining cash will be disbursed in 2015.
	In 2012, the Company had a compensating balance requirement for one of its lines of credit which was recorded as Restricted Cash – compensating balance. This requirement was removed in 2013.
Accounts Receivable	Accounts Receivable
	Accounts receivable are stated at outstanding balances, less a reserve for doubtful accounts. The reserve for doubtful accounts is established through provisions charged against income. Accounts deemed to be uncollectible are charged against the reserve and subsequent recoveries, if any, are credited to the reserve. The reserve for doubtful accounts is maintained at a level considered adequate to provide for losses that can be reasonably anticipated. Management's periodic evaluation of the adequacy of the reserve is based on past experience, agings of the receivables, adverse situations that may affect a customer's ability to pay, current economic conditions, and other relevant factors. This evaluation is inherently subjective. Unpaid balances remaining after the stated payment terms are considered past due.
Revenue Recognition	Revenue Recognition
	Operating revenues include amounts billed to water customers on a cycle basis and unbilled amounts based on actual and estimated usage from the latest meter reading to the end of the accounting period. Operating revenues also include amounts billed to wastewater customers as either a flat monthly fee or a metered rate based on water consumption. The metered wastewater revenue includes actual and estimated usage from the latest meter reading to the end of the accounting period.
Materials and Supplies Inventories	Materials and Supplies Inventories
	Materials and supplies inventories are stated at cost.  Costs are determined using the average cost method.
Deferred Debt Expense	Deferred Debt Expense
	Deferred debt expense is amortized on a straight-line basis over the term of the related debt.
Notes Receivable	Notes Receivable
	Notes receivable are recorded at cost and represent amounts due from various municipalities for construction of water mains in their particular municipality. Management, considering current information and events regarding the borrowers' ability to repay their obligations, considers a note to be impaired when it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the note agreement. When a note is considered to be impaired, the carrying value of the note is written down. The amount of the impairment is measured based on the present value of expected future cash flows discounted at the note's effective interest rate.
Regulatory Assets and Liabilities	Regulatory Assets and Liabilities
	The Company is subject to the provisions of generally accepted accounting principles regarding rate-regulated entities. The accounting standards provide for the recognition of regulatory assets and liabilities as allowed by regulators for costs or credits that are reflected in current customer rates or are considered probable of being included in future rates. The regulatory assets or liabilities are then relieved as the cost or credit is reflected in rates. Regulatory assets represent costs that are expected to be fully recovered from customers in future rates while regulatory liabilities represent amounts that are expected to be refunded to customers in future rates. These deferred costs have been excluded from the Company's rate base and, therefore, no return is being earned on the unamortized balances.
	Regulatory assets and liabilities are comprised of the following:
		December 31,				Remaining Recovery
		2014		2013		Periods
	Assets
	Income taxes	$	15,800	$	5,653	Various
	Postretirement benefits		12,493		7,136	5 – 10 years
	Unrealized swap losses		2,561		1,611	1 – 15 years
	Utility plant retirement costs		1,561		1,408	5 years
	Service life study expenses		5		7	3 years
	Rate case filing expenses		194		308	2 years
			32,614		16,123
	Liabilities
	IRS TPR catch-up deduction		4,314		-	Not yet known
	Income taxes		806		809	1 – 50 years
		$	5,120	$	809
	The regulatory asset for income taxes include (a) deferred state income taxes related primarily to differences between book and tax depreciation expense, (b) deferred income taxes related to the differences that arise between specific asset improvement costs capitalized for book purposes and deducted as a repair expense for tax purposes, and (c) deferred income taxes associated with the gross-up of revenues related to the differences. These assets are recognized for ratemaking purposes on a cash or flow-through basis and will be recovered in rates as they reverse.
	Postretirement benefits include (a) deferred pension expense in excess of contributions made to the plans, and (b) the underfunded status of the pension plans.  The underfunded status represents the excess of the projected benefit obligation over the fair market value of the assets. Both are expected to be recovered in future years as additional contributions are made or market conditions improve. The recovery period is dependent on contributions made to the plans, plan asset performance and the discount rate used to value the obligations.  The period is estimated at between 5 and 10 years.
	The Company uses regulatory accounting treatment to defer the mark-to-market unrealized gains and losses on its interest rate swap to reflect that the gain or loss is included in the ratemaking formula when the transaction actually settles. The value of the swap as of the balance sheet date is recorded as part of other deferred credits.  Realized gains or losses on the swap will be recorded as interest expense in the statement of income over its remaining life of 15 years.
	Utility plant retirement costs, including cost of removal, represents costs already incurred which are expected to be recovered over a five-year period in rates, through depreciation expense.  Service life study and rate case filing expenses are deferred and amortized over their remaining lives of three and two years, respectively.
	The regulatory liability for the Internal Revenue Service, or IRS, tangible property regulations, or TPR, catch-up deduction represents the tax benefits anticipated to be realized on the Company's 2014 income tax return for qualifying capital expenditures made prior to 2014. The Company will seek approval from the PPUC to amortize this amount in the future.
	The regulatory liability for income taxes relates mainly to deferred investment tax credits, and additionally to deferred taxes related to postretirement death benefits and bad debts.  These liabilities will be given back to customers in rates as tax deductions occur over the next 1-50 years.
	Regulatory liabilities are part of other accrued expenses and other deferred credits on the balance sheets.
Other Assets	Other Assets
	Other assets consist mainly of the cash value of life insurance policies held as an investment by the Company for reimbursement of costs and benefits associated with its supplemental retirement and deferred compensation programs.
Customers' Advances for Construction	Customers' Advances for Construction
	Customer advances are cash payments from developers, municipalities, customers or builders for construction of utility plant, and are refundable upon completion of construction, as operating revenues are earned. If the Company loaned funds for construction to the customer, the refund amount is credited to the note receivable rather than paid out in cash. After all refunds to which the customer is entitled are made, any remaining balance is transferred to contributions in aid of construction. From 1986 to 1996 when customer advances were taxable income to the Company, additional funds were collected from customers to cover the taxes. Those funds were recorded as a liability within Customer Advances and are being amortized as deferred income over the tax life of the underlying assets.
Contributions in Aid of Construction	Contributions in Aid of Construction
	Contributions in Aid of Construction is composed of (i) direct, non-refundable contributions from developers, customers or builders for construction of water infrastructure and (ii) customer advances that have become non-refundable. Contributions in aid of construction are deducted from the Company's rate base, and therefore, no return is earned on property financed with contributions. The PPUC requires that contributions received remain on the Company's balance sheet indefinitely as a long-term liability.
Interest Rate Swap Agreement	Interest Rate Swap Agreement
	The Company is exposed to certain risks relating to its ongoing business operations. The primary risk managed by using derivative instruments is interest rate risk. The Company utilizes an interest rate swap agreement to convert its variable-rate debt to a fixed rate. The Company has designated the interest rate swap agreement as a cash flow hedge. Interest rate swaps are contracts in which a series of interest rate cash flows are exchanged over a prescribed period. The notional amount on which the interest payments are based is not exchanged. The interest rate swap agreement is classified as a financial derivative used for non-trading activities.
	The accounting standards regarding accounting for derivatives and hedging activities requires companies to recognize all derivative instruments as either assets or liabilities at fair value on the balance sheet. In accordance with the standards, the interest rate swap is recorded on the balance sheet in other deferred credits at fair value.
	The Company uses regulatory accounting treatment rather than hedge accounting to defer the unrealized gains and losses on its interest rate swap. Instead of the effective portion being recorded as other comprehensive income and the ineffective portion being recognized in earnings, the entire unrealized swap value is recorded as a regulatory asset. Based on current ratemaking treatment, the Company expects the gains and losses to be recognized in rates and in interest expense as the swap settlements occur.  Swap settlements are recorded in the income statement with the hedged item as interest expense.  During the year ended December 31, 2014, $368 was reclassified from regulatory assets to interest expense as a result of swap settlements.  The overall swap result was a (gain) loss of $1,318 in 2014, $(830) in 2013, and $358 in 2012.  During the twelve months ending December 31, 2015, the Company expects to reclassify $353 (before tax) from regulatory assets to interest expense.
	The interest rate swap will expire on October 1, 2029.
Income Taxes	Income Taxes
	Certain income and expense items are accounted for in different time periods for financial reporting than for income tax reporting purposes.
	Deferred income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and tax credit carryforwards.  Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. To the extent such income taxes increase or decrease future rates, an offsetting regulatory asset or liability has been recorded.
	Investment tax credits have been deferred and are being amortized to income over the average estimated service lives of the related assets.  As of December 31, 2014 and 2013, deferred investment tax credits amounted to $734 and $773, respectively.
	In anticipation of filing for a change in accounting method under the IRS TPR when the 2014 income tax return is filed, the Company adjusted its income tax provision for the effects of this change during the fourth quarter of 2014. Under the change in accounting method, the Company is permitted to deduct the costs of certain asset improvements that were previously being capitalized and depreciated for tax purposes as an expense on its income tax return. The Company is permitted to make this deduction for prior years (the "catch-up deduction") and each year going forward, beginning with 2014 (the "ongoing deduction"). The ongoing deduction resulted in a reduction in the effective income tax rate, a net reduction in income tax expense, and reduced the amount of income taxes currently payable. The catch-up deduction resulted in a decrease in current income taxes payable and an increase to regulatory liabilities. The Company will seek approval from the PPUC in the next few years to amortize the amount recorded as a regulatory liability. Both the ongoing and catch-up deductions resulted in increases to deferred tax liabilities and regulatory assets representing the appropriate book and tax basis difference on capital additions.
Allowance for Funds Used During Construction	Allowance for Funds Used During Construction
	Allowance for funds used during construction (AFUDC) represents the estimated cost of funds used for construction purposes during the period of construction.  These costs are reflected as non-cash income during the construction period and as an addition to the cost of plant constructed. AFUDC includes the net cost of borrowed funds and a rate of return on other funds. The PPUC approved rate of 10.04% was applied for 2014, 2013 and 2012.  AFUDC is recovered through water and wastewater rates as utility plant is depreciated.
Use of Estimates in the Preparation of Financial Statements	Use of Estimates in the Preparation of Financial Statements
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Impact of Recent Accounting Pronouncements	Impact of Recent Accounting Pronouncements
	In August 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-15, Disclosure of Uncertainties About an Entity's Ability to Continue as a Going Concern, which provides guidance on determining when and how reporting entities must disclose going-concern uncertainties in their financial statements. The new standard requires management to perform interim and annual assessments of an entity's ability to continue as a going concern within one year of the date of issuance of the entity's financial statements.  Further, an entity must provide certain disclosures if there is substantial doubt about the entity's ability to continue as a going concern.  The ASU is effective for fiscal years ending on or after December 15, 2016 and interim periods thereafter. The Company will comply with these assessments, but does not expect the adoption of this accounting standard to have any impact on its financial statements.
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers.  This ASU supersedes the revenue recognition requirements in Accounting Standards Codification 605—Revenue Recognition and most industry-specific guidance throughout the Codification. The standard requires that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. This ASU is effective for fiscal years beginning after December 15, 2016, and for interim periods within those fiscal years. The Company is in the process of assessing the impact of the adoption of ASU 2014-09 on its financial position, results of operations and cash flows.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Significant Accounting Policies
Schedule of Utility Plant	The following remaining lives are used for financial reporting purposes:
		December 31,				Approximate range
	Utility Plant Asset Category	2014		2013		of remaining lives
	Mains and accessories	$	164,627	$	157,113	10 – 84 years
	Services, meters and hydrants		63,479		61,206	19 – 55 years
	Operations structures, reservoirs and water tanks		43,654		42,692	11 – 41 years
	Pumping and treatment equipment		25,616		23,411	3 – 31 years
	Office, transportation and operating equipment		11,216		10,994	3 – 21 years
	Land and other non-depreciable assets		3,166		3,127	-
	Utility plant in service		311,758		298,543
	Construction work in progress		4,767		3,027	-
	Total Utility Plant	$	316,525	$	301,570
Regulatory Assets and Liabilities	Regulatory assets and liabilities are comprised of the following:
		December 31,				Remaining Recovery
		2014		2013		Periods
	Assets
	Income taxes	$	15,800	$	5,653	Various
	Postretirement benefits		12,493		7,136	5 – 10 years
	Unrealized swap losses		2,561		1,611	1 – 15 years
	Utility plant retirement costs		1,561		1,408	5 years
	Service life study expenses		5		7	3 years
	Rate case filing expenses		194		308	2 years
			32,614		16,123
	Liabilities
	IRS TPR catch-up deduction		4,314		-	Not yet known
	Income taxes		806		809	1 – 50 years
		$	5,120	$	809

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes
Provisions for Income Taxes	The provisions for income taxes consist of:
		2014			2013			2012
	Federal current	$	96		$	2,720		$	2,100
	State current		28			1,153			1,195
	Federal deferred		3,757			1,907			2,371
	State deferred		1,035			71			(21	)
	Federal investment tax credit, net of current utilization		(39	)		(39	)		(39	)
	Total income taxes	$	4,877		$	5,812		$	5,606
Reconciliation of Statutory Federal Tax Provision to Total Provision	A reconciliation of the statutory Federal tax provision (34%) to the total provision follows:
		2014			2013			2012
	Statutory Federal tax provision	$	5,563		$	5,258		$	5,069
	State income taxes, net of Federal benefit		702			808			775
	IRS TPR ongoing deduction		(1,342	)		-			-
	Tax-exempt interest		(37	)		(34	)		(33	)
	Amortization of investment tax credit		(39	)		(39	)		(39	)
	Cash value of life insurance		15			(32	)		(27	)
	Domestic production deduction		-			(154	)		(140	)
	Other, net		15			5			1
	Total income taxes	$	4,877		$	5,812		$	5,606
Deferred Tax Assets and Liabilities	The tax effects of temporary differences between book and tax balances that give rise to significant portions of the deferred tax assets and deferred tax liabilities as of December 31, 2014 and 2013 are summarized in the following table:
		2014			2013
	Deferred tax assets:
	Reserve for doubtful accounts	$	132		$	130
	Compensated absences		209			193
	Deferred compensation		1,452			1,265
	Customers' advances and contributions		8			20
	Deferred taxes associated with the gross-up of revenues necessary to return, in rates, the effect of temporary differences		123			114
	Pensions		4,185			2,010
	Tax loss carryover		836			-
	Contribution carryover		183			-
	Other costs deducted for book, not for tax		49			37
	Total deferred tax assets		7,177			3,769
	Deferred tax liabilities:
	Accelerated depreciation		34,000			32,260
	Basis differences from IRS TPR		5,917			-
	Investment tax credit		436			459
	Deferred taxes associated with the gross-up of revenues necessary to recover, in rates, the effect of temporary differences		6,210			2,080
	Tax effect of pension regulatory asset		5,071			2,897
	Other costs deducted for tax, not for book		509			448
	Total deferred tax liabilities		52,143			38,144
	Net deferred tax liability	$	44,966		$	34,375
	Reflected on balance sheets as:
	Current deferred tax asset	$	(1,058	)	$	(219	)
	Noncurrent deferred tax liability		46,024			34,594
	Net deferred tax liability	$	44,966		$	34,375

LongTerm_Debt_and_ShortTerm_Bo1

Long-Term Debt and Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2014
Long-Term Debt and Short-Term Borrowings [Abstract]
Long-Term Debt	Long-term debt as of December 31, 2014 and 2013 is summarized in the following table:
			2014				2013
	4.05% Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series A, due 2016		$	2,350			$	2,350
	5.00% Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series A, due 2016			4,950				4,950
	10.17% Senior Notes, Series A, due 2019			6,000				6,000
	9.60% Senior Notes, Series B, due 2019			5,000				5,000
	1.00% Pennvest Loan, due 2019			205				248
	10.05% Senior Notes, Series C, due 2020			6,500				6,500
	8.43% Senior Notes, Series D, due 2022			7,500				7,500
	Variable Rate Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series 2008A, due 2029			12,000				12,000
	4.75% Industrial Development Authority Revenue Bonds, Series 2006, due 2036			10,500				10,500
	6.00% Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series 2008B, due 2038			-				14,880
	4.50 % Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Refunding Bonds, Series 2014, due 2038			14,880				-
	5.00% Monthly Senior Notes, Series 2010A, due 2040			15,000				15,000
	Total long-term debt			84,885				84,928
	Less current maturities			(43	)			(43	)
	Long-term portion		$	84,842			$	84,885
Payments Due by Year	Payments due by year:
	2015				2016				2017			2018			2019
		$	43			$	19,344			$	44		$	44		$	11,030

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Employee Benefit Plans
Obligations and Funded Status	The following table sets forth the plans' funded status as of December 31, 2014 and 2013.  The measurement of assets and obligations of the plans is as of December 31, 2014 and 2013.
	Obligations and Funded Status		2014				2013
	At December 31
	Change in Benefit Obligation
	Pension benefit obligation beginning of year		$	32,054			$	34,726
	Service cost			952				1,188
	Interest cost			1,444				1,280
	Actuarial (gain) loss			7,762				(4,074	)
	Plan amendments			(210	)			-
	Benefit payments			(1,118	)			(1,066	)
	Pension benefit obligation end of year			40,884				32,054
	Change in Plan Assets
	Fair value of plan assets beginning of year			27,102				22,666
	Actual return on plan assets			2,409				3,911
	Employer contributions			2,182				1,593
	Benefits paid			(1,118	)			(1,068	)
	Fair value of plan assets end of year			30,575				27,102
	Funded Status of Plans at End of Year		$	(10,309	)		$	(4,952	)
Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets	Changes in plan assets and benefit obligations recognized in regulatory assets are as follows:
			2014				2013
	Net (gain) loss arising during the period		$	7,339			$	(6,339	)
	Recognized net actuarial loss			(126	)			(698	)
	Recognized prior service cost			(197	)			(10	)
	Total changes in regulatory asset during the year		$	7,016			$	(7,047	)
Amounts Recognized in Regulatory Assets That Have Not Yet Been Recognized as Components of Net Periodic Benefit Cost	Amounts recognized in regulatory assets that have not yet been recognized as components of net periodic benefit cost consist of the following at December 31:
			2014				2013
	Net loss		$	11,978			$	4,765
	Prior service (credit) cost			(140	)			57
	Regulatory asset		$	11,838			$	4,822
Components of Net Periodic Benefit Cost	Components of Net Periodic Benefit Cost are as follows:
			2014				2013				2012
	Service cost		$	952			$	1,188			$	1,050
	Interest cost			1,444				1,280				1,288
	Expected return on plan assets			(1,986	)			(1,644	)			(1,441	)
	Amortization of loss			126				698				641
	Amortization of prior service (credit) cost			(13	)			10				17
	Rate-regulated adjustment			1,659				61				38
	Net periodic benefit cost		$	2,182			$	1,593			$	1,593
Regulatory Assets to be Reclassified Into Net Periodic Benefit Cost Over Next Fiscal Year	The estimated costs for the defined benefit pension plans relating to the December 31, 2014 balance sheet that will be amortized from regulatory assets into net periodic benefit cost over the next fiscal year are as follows:
	Net loss		$	690
	Net prior service credit			(13	)
			$	677
Benefit Payments Expected to be Paid	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid in each of the next five years and the subsequent five years in the aggregate:
	2015				2016				2017				2018				2019					2020-2024
		$	1,544			$	1,584			$	1,576			$	1,727			$	1,861		$	10,278
Projected Benefit Obligation and Fair Value of Plan Assets	The following tables show the projected benefit obligation, the accumulated benefit obligation and the fair value of plan assets as of December 31:
			2014				2013
	Projected benefit obligation		$	40,884			$	32,054
	Fair value of plan assets			30,575				27,102
Accumulated Benefit Obligation and Fair Value of Plan Assets			2014				2013
	Accumulated benefit obligation		$	37,500			$	29,279
	Fair value of plan assets			30,575				27,102
Weighted-Average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost	Weighted-average assumptions used to determine benefit obligations at December 31:
			2014				2013
	Discount rate			3.8	%			4.65	%
	Rate of compensation increase			3	%			3	%
	Weighted-average assumptions used to determine net periodic benefit cost for years ended December 31:
			2014				2013				2012
	Discount rate			4.65	%			3.75	%			4.25	%
	Expected long-term return on plan assets			7	%			7	%			7	%
	Rate of compensation increase			3	%			3	%			3	%
Fair Values of Pension Plan Assets	The fair values of the Company's pension plan assets at December 31, 2014 and 2013 by asset category and fair value hierarchy level are as follows.  The majority of the valuations are based on quoted prices on active markets (Level 1), with the remaining valuations based on broker/dealer quotes, active market makers, models, and yield curves (Level 2).
			Total Fair Value								Quoted Prices in Active Markets for Identical Assets (Level 1)								Significant Other Observable Inputs
																			(Level 2)
	Asset Category		2014				2013				2014				2013				2014			2013
	Cash and Money Market Funds (a)		$	1,064			$	621			$	1,064			$	621			$	-		$	-
	Equity Securities:
	Common Equity Securities (b)			3,031				5,136				3,031				5,136				-			-
	Equity Mutual Funds (c)			16,380				13,907				16,380				13,907				-			-
	Fixed Income Securities:
	U.S. Treasury Obligations			831				815				-				-				831			815
	Corporate and Foreign Bonds (d)			1,620				398				-				-				1,620			398
	Fixed Income Mutual Funds (e)			7,649				6,225				7,649				6,225				-			-
	Total Plan Assets		$	30,575			$	27,102			$	28,124			$	25,889			$	2,451		$	1,213
		(a)	The portfolios are designed to keep approximately three months of distributions in immediately available funds.  The Company was more heavily-weighted in cash as of December 31, 2014 some as a precaution, and some due to investments made but not settled prior to year end.
		(b)	This category includes investments in U.S. common stocks and foreign stocks trading in the U.S. widely distributed among consumer discretionary, consumer staples, healthcare, information technology, financial services, materials, industrials, energy and utilities. The individual stocks are primarily large cap stocks which track with the S&P 500 with the exception of $447 (1.5% of total plan assets) which is invested in York Water Company common stock.
		(c)	This category currently includes a majority of investments in closed-end mutual funds as well as domestic equity mutual funds and international mutual funds which give the portfolio exposure to mid and large cap index funds as well as international diversified index funds.
		(d)	This category currently includes only U.S. corporate bonds and notes widely distributed among consumer discretionary, consumer staples, healthcare, information technology, financial services, energy and utilities.
		(e)	This category includes fixed income investments in mutual funds which include government, corporate and mortgage securities of both the U.S. and other countries. The mortgage-backed securities and non-U.S. corporate and sovereign investments add further diversity to the fixed income portion of the portfolio.

Notes_Receivable_and_Customers1

Notes Receivable and Customers' Advances for Construction (Tables)	12 Months Ended
	Dec. 31, 2014
Notes Receivable and Customers' Advances for Construction [Abstract]
Amounts Related to Water District Projects	Included in the accompanying balance sheets at December 31, 2014 and 2013 were the following amounts related to these projects.
		2014		2013
	Notes receivable, including interest	$	266	$	306
	Customers' advances for construction		626		928

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value of Financial Instruments [Abstract]
Fair Value of Interest Rate Swap	The Company has recorded its interest rate swap liability at fair value in accordance with the standards.  The liability is recorded under the caption "Other deferred credits" on the balance sheet.  The table below illustrates the fair value of the interest rate swap as of the end of the reporting period.
	Description	31-Dec-14	Fair Value Measurements
			at Reporting Date Using
			Significant Other Observable Inputs (Level 2)
	Interest Rate Swap	$2,592	$2,592
	Fair values are measured as the present value of all expected future cash flows based on the LIBOR-based swap yield curve as of the date of the valuation.  These inputs to this calculation are deemed to be Level 2 inputs.  The balance sheet carrying value reflects the Company's credit quality as of December 31, 2014.  The rate used in discounting all prospective cash flows anticipated to be made under this swap reflects a representation of the yield to maturity for 30-year debt on utilities rated A- as of December 31, 2014.  The use of the Company's credit quality resulted in a reduction in the swap liability of $75.  The fair value of the swap reflecting the Company's credit quality as of December 31, 2013 is shown in the table below.
	Description	31-Dec-13	Fair Value Measurements
			at Reporting Date Using
			Significant Other Observable Inputs (Level 2)
	Interest Rate Swap	$1,641	$1,641

Taxes_Other_than_Income_Taxes_

Taxes Other than Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Taxes Other Than Income Taxes [Abstract]
Components of Taxes Other Than Income Taxes	The following table provides the components of taxes other than income taxes:
		2014		2013		2012
	Regulatory Assessment	$	218	$	220	$	228
	Property		339		364		342
	Payroll, net of amounts capitalized		494		462		458
	Capital Stock		59		75		151
	Other		1		1		1
	Total taxes other than income taxes	$	1,111	$	1,122	$	1,180

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Data (Unaudited) [Abstract]
Selected Quarterly Financial Data		First		Second		Third		Fourth		Year
	2014
	Operating revenues	$	10,571	$	11,768	$	12,062	$	11,499	$	45,900
	Operating income		4,758		5,800		6,092		5,427		22,077
	Net income*		2,111		2,757		3,065		3,551		11,484
	Basic earnings per share		0.16		0.22		0.23		0.28		0.89
	Dividends declared per share		0.1431		0.1431		0.1431		0.1495		0.5788
	* Fourth quarter net income includes a tax benefit of $1,342 for the full year 2014 due to the implementation of the IRS TPR.
	2013
	Operating revenues	$	10,069	$	10,737	$	10,912	$	10,665	$	42,383
	Operating income		4,773		5,301		5,367		5,320		20,761
	Net income		2,139		2,342		2,535		2,638		9,654
	Basic earnings per share		0.17		0.18		0.19		0.21		0.75
	Dividends declared per share		0.1383		0.1383		0.1383		0.1431		0.558

Significant_Accounting_Policie3

Significant Accounting Policies (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Significant Accounting Policies
Utility plant acquisition adjustments	$3,522	$2,900
Amortization of utility plant acquisition adjustments	54	50	50
Deferred investment tax credits	734	773
PPUC approved rate for AFUDC (in hundredths)	10.04%	10.04%	10.04%
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	316,525	301,570
Effective rate of depreciation (in hundredths)	2.26%	2.28%	2.13%
Regulatory Assets [Abstract]
Regulatory assets	32,614	16,123
Regulatory Liabilities [Abstract]
Regulatory liability	5,120	809
Interest Rate Swap Derivatives [Abstract]
Interest rate swap settlements reclassified to interest expense	368
Interest rate swap gain (loss) capitalized	1,318	-830	358
Interest rate swap settlements to be reclassified during the next 12 months	353
Interest rate swap expire period	1-Oct-29
Income Taxes [Member]
Regulatory Liabilities [Abstract]
Regulatory liability	806	809
IRS TPR Catch-Up Deduction [Member]
Regulatory Liabilities [Abstract]
Regulatory liability	4,314	0
Income Taxes [Member]
Regulatory Assets [Abstract]
Regulatory assets	15,800	5,653
Postretirement Benefits [Member]
Regulatory Assets [Abstract]
Regulatory assets	12,493	7,136
Unrealized Swap Losses [Member]
Regulatory Assets [Abstract]
Regulatory assets	2,561	1,611
Utility Plant Retirement Costs [Member]
Regulatory Assets [Abstract]
Regulatory assets	1,561	1,408
Remaining recovery periods	5 years
Rate Case Filing Expenses [Member]
Regulatory Assets [Abstract]
Regulatory assets	194	308
Remaining recovery periods	2 years
Service Life Study Expenses [Member]
Regulatory Assets [Abstract]
Regulatory assets	5	7
Remaining recovery periods	3 years
Minimum [Member] | Income Taxes [Member]
Regulatory Liabilities [Abstract]
Remaining recovery periods	1 year
Minimum [Member] | Postretirement Benefits [Member]
Regulatory Assets [Abstract]
Remaining recovery periods	5 years
Minimum [Member] | Unrealized Swap Losses [Member]
Regulatory Assets [Abstract]
Remaining recovery periods	1 year
Maximum [Member] | Income Taxes [Member]
Regulatory Liabilities [Abstract]
Remaining recovery periods	50 years
Maximum [Member] | Postretirement Benefits [Member]
Regulatory Assets [Abstract]
Remaining recovery periods	10 years
Maximum [Member] | Unrealized Swap Losses [Member]
Regulatory Assets [Abstract]
Remaining recovery periods	15 years
Mains and Accessories [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	164,627	157,113
Mains and Accessories [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	10 years
Mains and Accessories [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	84 years
Services, meters and hydrants [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	63,479	61,206
Services, meters and hydrants [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	19 years
Services, meters and hydrants [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	55 years
Operations structures, reservoirs and water tanks [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	43,654	42,692
Operations structures, reservoirs and water tanks [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	11 years
Operations structures, reservoirs and water tanks [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	41 years
Pumping and treatment equipment [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	25,616	23,411
Pumping and treatment equipment [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	3 years
Pumping and treatment equipment [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	31 years
Office, transportation and operating equipment [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	11,216	10,994
Office, transportation and operating equipment [Member] | Minimum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	3 years
Office, transportation and operating equipment [Member] | Maximum [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Approximate range of remaining lives	21 years
Land and other non-depreciable assets [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	3,166	3,127
Approximate range of remaining lives	0 years
Utility plant in service [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	311,758	298,543
Construction work in progress [Member]
Public Utilities, Property, Plant and Equipment, Plant in Service [Abstract]
Total Utility Plant	$4,767	$3,027
Approximate range of remaining lives	0 years

Acquisitions_Details

Acquisitions (Details) (USD $)	12 Months Ended			3 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013
Business Acquisition [Line Items]
Purchase price	$369	$28	$661
Asbury Pointe Water and Sewer Company [Member]
Business Acquisition [Line Items]
Date of agreement	31-Jul-12
Effective date of acquisition	1-Aug-12
Number of customers acquired	240
Purchase price	359
Change in acquisition adjustment				1
Acquisition adjustment	368		367
York Starview, LP [Member]
Business Acquisition [Line Items]
Date of agreement	16-Aug-12
Effective date of acquisition	16-Aug-12
Number of customers acquired	240
Purchase price	131
Acquisition adjustment	36
Section A Water Corporation [Member]
Business Acquisition [Line Items]
Date of agreement	12-Oct-12
Effective date of acquisition	15-Oct-12
Number of customers acquired	100
Purchase price	171
Acquisition adjustment	35
Windy Brae Mobile Home Park [Member]
Business Acquisition [Line Items]
Date of agreement	7-Mar-13
Effective date of acquisition	11-Mar-13
Number of customers acquired	135
Purchase price	29
Acquisition adjustment	45
Wastewater Facilities of East Prospect Borough Authority [Member]
Business Acquisition [Line Items]
Date of agreement	7-Feb-14
Effective date of acquisition	8-Feb-14
Number of customers acquired	400
Purchase price	281
Acquisition adjustment	667
Water Assets of Forest Lakes Water Association [Member]
Business Acquisition [Line Items]
Date of agreement	30-May-14
Effective date of acquisition	2-Jun-14
Number of customers acquired	70
Purchase price	18
Acquisition adjustment	9
Water Assets of Lincoln Estates Mobile Home Park [Member]
Business Acquisition [Line Items]
Date of agreement	20-Nov-14
Effective date of acquisition	24-Nov-14
Number of customers acquired	200
Purchase price	$70

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Position
Provisions for income taxes [Abstract]
Federal current	$96	$2,720	$2,100
State current	28	1,153	1,195
Federal deferred	3,757	1,907	2,371
State deferred	1,035	71	-21
Federal investment tax credit, net of current utilization	-39	-39	-39
Total income taxes	4,877	5,812	5,606
Reconciliation of statutory Federal tax provision to total provision [Abstract]
Statutory Federal tax percentage (in hundredths)	34.00%	34.00%	34.00%
Statutory Federal tax provision	5,563	5,258	5,069
State income taxes, net of Federal benefit	702	808	775
IRS TPR ongoing deduction	-1,342	0	0
Tax-exempt interest	-37	-34	-33
Amortization of investment tax credit	-39	-39	-39
Cash value of life insurance	15	-32	-27
Domestic production deduction	0	-154	-140
Other, net	15	5	1
Total income taxes	4,877	5,812	5,606
Regulatory liabilities [Abstract]
Regulatory liability	5,120	809
Deferred tax assets [Abstract]
Reserve for doubtful accounts	132	130
Compensated absences	209	193
Deferred compensation	1,452	1,265
Customers' advances and contributions	8	20
Deferred taxes associated with the gross-up of revenues necessary to return, in rates, the effect of temporary differences	123	114
Pensions	4,185	2,010
Tax loss carryover	836	0
Contribution carryover	183	0
Other costs deducted for book, not for tax	49	37
Total deferred tax assets	7,177	3,769
Deferred tax liabilities [Abstract]
Accelerated depreciation	34,000	32,260
Basis differences from IRS TPR	5,917	0
Investment tax credit	436	459
Deferred taxes associated with the gross-up of revenues necessary to recover, in rates, the effect of temporary differences	6,210	2,080
Tax effect of pension regulatory asset	5,071	2,897
Other costs deducted for tax, not for book	509	448
Total deferred tax liabilities	52,143	38,144
Net deferred tax liability	44,966	34,375
Reflected on balance sheets as [Abstract]
Current deferred tax asset	-1,058	-219
Noncurrent deferred tax liability	46,024	34,594
Net deferred tax liability	44,966	34,375
Other income tax disclosures [Abstract]
Contribution carryovers	451
Contribution carryovers, expiration date	31-Dec-19
Uncertain tax positions	0
Number of new tax positions taken	1
Interest or penalties	0	0	0
Maximum [Member]
Other income tax disclosures [Abstract]
Open tax year	2013
Minimum [Member]
Other income tax disclosures [Abstract]
Open tax year	2011
Valuation Allowance of Deferred Tax Assets [Member]
Other income tax disclosures [Abstract]
Valuation allowance	0	0
Federal [Member]
Other income tax disclosures [Abstract]
Tax loss carryover	1,887
Tax loss carryover, expiration date	31-Dec-34
State [Member]
Other income tax disclosures [Abstract]
Tax loss carryover	2,956
Tax loss carryover, expiration date	31-Dec-34
IRS TPR Catch-Up Deduction [Member]
Regulatory liabilities [Abstract]
Regulatory liability	$4,314	$0

LongTerm_Debt_and_ShortTerm_Bo2

Long-Term Debt and Short-Term Borrowings (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt	$84,885	$84,928
Less current maturities	-43	-43
Long-term portion	84,842	84,885
Payments due by year [Abstract]
2015	43
2016	19,344
2017	44
2018	44
2019	11,030
Line of Credit Facility [Abstract]
Unsecured lines of credit aggregating amount	29,000
Number of banks in which unsecured line of credit maintained	3
Debt Covenants and Restrictions [Abstract]
Maximum borrowing percentage of utility plant (in hundredths)	60.00%
Base amount added to annual net income to determine restriction on dividends and stock acquisition	1,500
Unsecured Line of Credit, First Note [Member]
Line of Credit Facility [Abstract]
Unsecured lines of credit aggregating amount	13,000
Line of credit, maturity period	2 years
Line of credit, maturity date	1-May-16
Line of credit amount outstanding	0	0
Unsecured Line of Credit, First Note [Member] | LIBOR [Member]
Line of Credit Facility [Abstract]
Basis for interest rate	1.20%
Unsecured Line of Credit, Second Note [Member]
Line of Credit Facility [Abstract]
Unsecured lines of credit aggregating amount	11,000
Line of credit, maturity date	1-May-16
Line of credit compensating balance requirement	0	500
Line of credit amount outstanding	0	0
Unsecured Line of Credit, Second Note [Member] | LIBOR [Member]
Line of Credit Facility [Abstract]
Basis for interest rate	1.25%
Unsecured Line of Credit, Third Note [Member]
Line of Credit Facility [Abstract]
Unsecured lines of credit aggregating amount	5,000
Line of credit, maturity date	1-Jun-15
Line of credit amount outstanding	0	0
Unsecured Line of Credit, Third Note [Member] | LIBOR [Member]
Line of Credit Facility [Abstract]
Basis for interest rate	1.50%
Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series A, due 2016, 4.05 Percent [Member]
Debt Instrument [Line Items]
Long-term debt	2,350	2,350
Interest rate (in hundredths)	4.05%
Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series A, due 2016, 5.00 Percent [Member
Debt Instrument [Line Items]
Long-term debt	4,950	4,950
Interest rate (in hundredths)	5.00%
Senior Notes, Series A, due 2019, 10.17 percent [Member]
Debt Instrument [Line Items]
Long-term debt	6,000	6,000
Interest rate (in hundredths)	10.17%
Senior Notes, Series B, due 2019, 9.6 percent [Member]
Debt Instrument [Line Items]
Long-term debt	5,000	5,000
Interest rate (in hundredths)	9.60%
Pennvest Loan, due 2019, 1.00 percent [Member]
Debt Instrument [Line Items]
Long-term debt	205	248
Interest rate (in hundredths)	1.00%
Debt Covenants and Restrictions [Abstract]
Amount of receivables pledged as collateral	800
Senior Notes, Series C, due 2020, 10.05 percent [Member]
Debt Instrument [Line Items]
Long-term debt	6,500	6,500
Interest rate (in hundredths)	10.05%
Senior Notes, Series D, due 2022, 8.43 percent [Member]
Debt Instrument [Line Items]
Long-term debt	7,500	7,500
Interest rate (in hundredths)	8.43%
Variable Rate Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds Series 2008A due 2029 [Member]
Debt Instrument [Line Items]
Long-term debt	12,000	12,000
Payments due by year [Abstract]
2016	12,000
Long-term debt [Abstract]
Face value	12,000
Variable interest rate, annual average (in hundredths)	0.07%	0.13%
Variable interest rate, at year end (in hundredths)	0.05%	0.09%
Period in which to reimburse bank for purchase price of tendered bonds that have not been remarketed	14 months
Variable Rate Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds Series 2008A due 2029 [Member] | Interest Rate Swap [Member]
Interest Rate Swap Agreement Abstract]
Notional amount of swap	12,000
Potential payment to counterparty	2,667
Fixed interest rate (in hundredths)	3.16%
Net payment rate on swap (in hundredths)	3.07%	3.05%
Interest rate spread in basis points	-0.05%	-0.01%
Overall effective rate, including variable interest and swap payments (in hundredths)	3.11%	3.15%
Variable Rate Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds Series 2008A due 2029 [Member] | LIBOR [Member] | Interest Rate Swap [Member]
Interest Rate Swap Agreement Abstract]
Percentage of variable interest rate (in hundredths)	59.00%
Variable Rate Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds Series 2008A due 2029 [Member] | Letter of Credit [Member]
Line of Credit Facility [Abstract]
Line of credit, maturity date	30-Jun-17
Industrial Development Authority Revenue Bonds, series 2006, due 2036, 4.75 percent [Member]
Debt Instrument [Line Items]
Long-term debt	10,500	10,500
Interest rate (in hundredths)	4.75%
Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Bonds, Series 2008B, due 2038, 6.00 percent [Member]
Debt Instrument [Line Items]
Long-term debt	0	14,880
Interest rate (in hundredths)	6.00%
Long-term debt [Abstract]
Special provision, repayment of bonds	0	5
4.50% Pennsylvania Economic Development Financing Authority Exempt Facilities Revenue Refunding Bonds, Series 2014, due 2038 [Member]
Debt Instrument [Line Items]
Long-term debt	14,880	0
Interest rate (in hundredths)	4.50%
Long-term debt [Abstract]
Special provision, amount to be redeemed per individual interest, per year, maximum	25
Special provision, amount to be redeemed in the aggregate, per year, maximum	300
Special provision, repayment of bonds	0
Monthly Senior Notes, Series 2010A, due 2040, 5.00 percent [Member]
Debt Instrument [Line Items]
Long-term debt	$15,000	$15,000
Interest rate (in hundredths)	5.00%

Common_Stock_and_Earnings_Per_1

Common Stock and Earnings Per Share (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Common Stock And Earnings Per Share [Abstract]
Weighted average number of shares outstanding (in shares)	12,879,912	12,928,040	12,847,160
Common Stock Issues by Plan [Line Items]
Number of shares authorized to be repurchased under the stock repurchase program (in shares)	1,200,000
Number of shares repurchased and retired under the stock repurchase program (in shares)	282,570	94,414
Number of remaining shares authorized to be repurchased under the stock repurchase program (in shares)	823,016
Employee Stock Purchase Plan [Member]
Common Stock Issues by Plan [Line Items]
Minimum service period required to purchase shares	90 days
Maximum gross compensation allocated to purchase shares	10.00%
Percentage of purchase price of fair market value (in hundredths)	95.00%
Shares issued during period (in shares)	7,431	6,711	7,776
Number of authorized shares remains unissued (in shares)	88,128
Direct Stock Purchase and Sale Portion of Plan [Member]
Common Stock Issues by Plan [Line Items]
Percentage of purchase price of fair market value (in hundredths)	100.00%
Optional Dividend Reinvestment Portion of Plan [Member]
Common Stock Issues by Plan [Line Items]
Percentage of purchase price of fair market value (in hundredths)	95.00%
2008 Dividend Reinvestment and Direct Stock Purchase and Sale Plan [Member]
Common Stock Issues by Plan [Line Items]
Shares issued during period (in shares)	0	112,163	119,186
2013 Dividend Reinvestment and Direct Stock Purchase Plan [Member]
Common Stock Issues by Plan [Line Items]
Shares authorized under registration statement	500,000
Shares issued during period (in shares)	126,379	36,188
Number of authorized shares remains unissued (in shares)	337,433

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
	Employee
Defined Contribution Plan [Abstract]
Maximum elective employee contributions (in hundredths)	15.00%
Company matching contributions (in hundredths)	100.00%
Maximum annual Company contribution for each employee	$2,800
Number of employees participating in enhanced feature of plan	16
Company's total contributions to defined contribution plan	239,000		222,000		244,000
Maximum annual Company contribution as a percentage of employee's compensation (in hundredths)	4.00%
Annual Company discretionary contribution	1,200
Deferred Compensation [Abstract]
Present value of future obligations	3,576,000		3,115,000
Total cash value of insurance policies	3,567,000		3,591,000
Company's expenses under deferred compensation plans	658,000		-91,000		358,000
Other Postretirement Benefits [Abstract]
Amount payable upon retiree's death	2,000
Present value of future obligations	110,000		91,000
Company's expenses under other postretirement benefit plans	25,000		-14,000		15,000
Defined Benefit Pension Plans Combined [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum period of eligible service	30 years
Decrease in discount rate (in hundredths)	-0.85%
Threshold for amortization of gains and losses	10.00%
Estimated employer contributions	2,300,000
Change in Benefit Obligation [Abstract]
Pension benefit obligation beginning of year	32,054,000		34,726,000
Service cost	952,000		1,188,000		1,050,000
Interest cost	1,444,000		1,280,000		1,288,000
Actuarial (gain) loss	7,762,000		-4,074,000
Plan amendments	-210,000		0
Benefit payments	-1,118,000		-1,066,000
Pension benefit obligation end of year	40,884,000		32,054,000		34,726,000
Change in Plan Assets [Abstract]
Fair value of plan assets beginning of year	27,102,000		22,666,000
Actual return on plan assets	2,409,000		3,911,000
Employer contributions	2,182,000		1,593,000
Benefits paid	-1,118,000		-1,068,000
Fair value of plan assets end of year	30,575,000		27,102,000		22,666,000
Funded Status of Plans at End of Year	-10,309,000		-4,952,000
Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets [Abstract]
Net (gain) loss arising during the period	7,339,000		-6,339,000
Recognized net actuarial loss	-126,000		-698,000		-641,000
Recognized prior service cost	-197,000		-10,000
Total changes in regulatory asset during the year	7,016,000		-7,047,000
Amounts recognized in regulatory assets that have not yet been recognized as components of net periodic benefit cost [Abstract]
Net loss	11,978,000		4,765,000
Prior service (credit) cost	-140,000		57,000
Regulatory asset	11,838,000		4,822,000
Components of Net Periodic Benefit Cost [Abstract]
Service cost	952,000		1,188,000		1,050,000
Interest cost	1,444,000		1,280,000		1,288,000
Expected return on plan assets	-1,986,000		-1,644,000		-1,441,000
Amortization of loss	126,000		698,000		641,000
Amortization of prior service (credit) cost	-13,000		10,000		17,000
Rate-regulated adjustment	1,659,000		61,000		38,000
Net periodic benefit cost	2,182,000		1,593,000		1,593,000
Change in defined benefit plan regulatory asset from pension contribution greater (less) than net periodic benefit cost	1,659,000
Regulatory assets to be reclassified into net periodic benefit cost over next fiscal year [Abstract]
Net loss	690,000
Net prior service credit	-13,000
Regulatory assets to be reclassified into net periodic benefit cost during the next 12 months	677,000
Benefit payments expected to be paid for future services [Abstract]
2015	1,544,000
2016	1,584,000
2017	1,576,000
2018	1,727,000
2019	1,861,000
2020-2024	10,278,000
Projected benefit obligation and fair value of plan assets [Abstract]
Projected benefit obligation	40,884,000		32,054,000		34,726,000
Fair value of plan assets	30,575,000		27,102,000		22,666,000
Accumulated benefit obligation and fair value of plan assets [Abstract]
Accumulated benefit obligation	37,500,000		29,279,000
Fair value of plan assets	30,575,000		27,102,000		22,666,000
Weighted-average assumptions used to determine benefit obligations [Abstract]
Discount rate (in hundredths)	3.80%		4.65%
Rate of compensation increase (in hundredths)	3.00%		3.00%
Weighted-average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate (in hundredths)	4.65%		3.75%		4.25%
Expected long-term return on plan assets (in hundredths)	7.00%		7.00%		7.00%
Rate of compensation increase (in hundredths)	3.00%		3.00%		3.00%
Target asset allocations [Abstract]
Percentage by which the return on plan assets should exceed the annual rate of inflation (in hundredths)	3.00%
Maximum equity securities holdings in any one company (in hundredths)	5.00%
Minimum number of individual stocks that must be included in the domestic stock portfolio	20
Minimum number of individual stocks that must be included in the international stock portfolio	30
Maximum fixed income securities holdings in any single issuer (in hundredths)	5.00%
Fair value of pension plan assets [Abstract]
Fair value of plan assets	30,575,000		27,102,000		22,666,000
Fair value of plan assets invested in Company stock	447,000
Percentage of fair value of plan assets invested in Company stock (in hundredths)	1.50%
Defined Benefit Pension Plans Combined [Member] | Cash and Money Market Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	1,064,000	[1]	621,000	[1]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	1,064,000	[1]	621,000	[1]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	1,064,000	[1]	621,000	[1]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	1,064,000	[1]	621,000	[1]
Defined Benefit Pension Plans Combined [Member] | Common Equity Securities [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	3,031,000	[2]	5,136,000	[2]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	3,031,000	[2]	5,136,000	[2]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	3,031,000	[2]	5,136,000	[2]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	3,031,000	[2]	5,136,000	[2]
Defined Benefit Pension Plans Combined [Member] | Equity Mutual Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	16,380,000	[3]	13,907,000	[3]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	16,380,000	[3]	13,907,000	[3]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	16,380,000	[3]	13,907,000	[3]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	16,380,000	[3]	13,907,000	[3]
Defined Benefit Pension Plans Combined [Member] | U.S. Treasury Obligations [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	831,000		815,000
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	831,000		815,000
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	831,000		815,000
Fair value of pension plan assets [Abstract]
Fair value of plan assets	831,000		815,000
Defined Benefit Pension Plans Combined [Member] | Corporate and Foreign Bonds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	1,620,000	[4]	398,000	[4]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	1,620,000	[4]	398,000	[4]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	1,620,000	[4]	398,000	[4]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	1,620,000	[4]	398,000	[4]
Defined Benefit Pension Plans Combined [Member] | Fixed Income Mutual Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	7,649,000	[5]	6,225,000	[5]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	7,649,000	[5]	6,225,000	[5]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	7,649,000	[5]	6,225,000	[5]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	7,649,000	[5]	6,225,000	[5]
Defined Benefit Pension Plans Combined [Member] | Minimum [Member]
Target asset allocations [Abstract]
Investment performance objectives benchmark period	3 years
Maximum equity securities holdings in any one company (in hundredths)	20.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Large Cap [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	60.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Mid Cap [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Small Cap [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | International Developed Nations [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | International Emerging Nations [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | International [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | U.S. Treasuries [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	15.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Federal Agency Securities [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Corporate Bonds [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Mortgage-Backed Securities [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	15.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | High Yield Bonds [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Cash and Money Market Funds [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	0.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Equity Securities [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	50.00%
Asset allocation of plan assets (in hundredths)	50.00%
Defined Benefit Pension Plans Combined [Member] | Minimum [Member] | Fixed Income Securities [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	30.00%
Asset allocation of plan assets (in hundredths)	30.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member]
Target asset allocations [Abstract]
Investment performance objectives benchmark period	5 years
Maximum equity securities holdings in any one company (in hundredths)	25.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Large Cap [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	95.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Mid Cap [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	25.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Small Cap [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	10.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | International Developed Nations [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	25.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | International Emerging Nations [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	10.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | International [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	20.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | U.S. Treasuries [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	55.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Federal Agency Securities [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	22.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Corporate Bonds [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	40.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Mortgage-Backed Securities [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	55.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | High Yield Bonds [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	20.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Cash and Money Market Funds [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	10.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Equity Securities [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	70.00%
Asset allocation of plan assets (in hundredths)	70.00%
Defined Benefit Pension Plans Combined [Member] | Maximum [Member] | Fixed Income Securities [Member]
Target asset allocations [Abstract]
Weighted-average target asset allocations (in hundredths)	50.00%
Asset allocation of plan assets (in hundredths)	50.00%
Defined Benefit Pension Plans Combined [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	28,124,000		25,889,000
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	28,124,000		25,889,000
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	28,124,000		25,889,000
Fair value of pension plan assets [Abstract]
Fair value of plan assets	28,124,000		25,889,000
Defined Benefit Pension Plans Combined [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash and Money Market Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	1,064,000	[1]	621,000	[1]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	1,064,000	[1]	621,000	[1]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	1,064,000	[1]	621,000	[1]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	1,064,000	[1]	621,000	[1]
Defined Benefit Pension Plans Combined [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Common Equity Securities [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	3,031,000	[2]	5,136,000	[2]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	3,031,000	[2]	5,136,000	[2]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	3,031,000	[2]	5,136,000	[2]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	3,031,000	[2]	5,136,000	[2]
Defined Benefit Pension Plans Combined [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Mutual Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	16,380,000	[3]	13,907,000	[3]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	16,380,000	[3]	13,907,000	[3]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	16,380,000	[3]	13,907,000	[3]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	16,380,000	[3]	13,907,000	[3]
Defined Benefit Pension Plans Combined [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury Obligations [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	0		0
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Fair value of pension plan assets [Abstract]
Fair value of plan assets	0		0
Defined Benefit Pension Plans Combined [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate and Foreign Bonds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	0	[4]	0	[4]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[4]	0	[4]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[4]	0	[4]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	0	[4]	0	[4]
Defined Benefit Pension Plans Combined [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income Mutual Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	7,649,000	[5]	6,225,000	[5]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	7,649,000	[5]	6,225,000	[5]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	7,649,000	[5]	6,225,000	[5]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	7,649,000	[5]	6,225,000	[5]
Defined Benefit Pension Plans Combined [Member] | Significant Other Observable Inputs (Level 2) [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	2,451,000		1,213,000
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	2,451,000		1,213,000
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	2,451,000		1,213,000
Fair value of pension plan assets [Abstract]
Fair value of plan assets	2,451,000		1,213,000
Defined Benefit Pension Plans Combined [Member] | Significant Other Observable Inputs (Level 2) [Member] | Cash and Money Market Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	0	[1]	0	[1]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[1]	0	[1]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[1]	0	[1]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	0	[1]	0	[1]
Defined Benefit Pension Plans Combined [Member] | Significant Other Observable Inputs (Level 2) [Member] | Common Equity Securities [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	0	[2]	0	[2]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[2]	0	[2]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[2]	0	[2]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	0	[2]	0	[2]
Defined Benefit Pension Plans Combined [Member] | Significant Other Observable Inputs (Level 2) [Member] | Equity Mutual Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	0	[3]	0	[3]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[3]	0	[3]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[3]	0	[3]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	0	[3]	0	[3]
Defined Benefit Pension Plans Combined [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury Obligations [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	831,000		815,000
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	831,000		815,000
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	831,000		815,000
Fair value of pension plan assets [Abstract]
Fair value of plan assets	831,000		815,000
Defined Benefit Pension Plans Combined [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate and Foreign Bonds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	1,620,000	[4]	398,000	[4]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	1,620,000	[4]	398,000	[4]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	1,620,000	[4]	398,000	[4]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	1,620,000	[4]	398,000	[4]
Defined Benefit Pension Plans Combined [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fixed Income Mutual Funds [Member]
Change in Plan Assets [Abstract]
Fair value of plan assets end of year	0	[5]	0	[5]
Projected benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[5]	0	[5]
Accumulated benefit obligation and fair value of plan assets [Abstract]
Fair value of plan assets	0	[5]	0	[5]
Fair value of pension plan assets [Abstract]
Fair value of plan assets	$0	[5]	$0	[5]
[1]	The portfolios are designed to keep approximately three months of distributions in immediately available funds. The Company was more heavily-weighted in cash as of December 31, 2014 some as a precaution, and some due to investments made but not settled prior to year end.
[2]	This category includes investments in U.S. common stocks and foreign stocks trading in the U.S. widely distributed among consumer discretionary, consumer staples, healthcare, information technology, financial services, materials, industrials, energy and utilities. The individual stocks are primarily large cap stocks which track with the S&P 500 with the exception of $447 (1.5% of total plan assets) which is invested in York Water Company common stock.
[3]	This category currently includes a majority of investments in closed-end mutual funds as well as domestic equity mutual funds and international mutual funds which give the portfolio exposure to mid and large cap index funds as well as international diversified index funds.
[4]	This category currently includes only U.S. corporate bonds and notes widely distributed among consumer discretionary, consumer staples, healthcare, information technology, financial services, energy and utilities.
[5]	This category includes fixed income investments in mutual funds which include government, corporate and mortgage securities of both the U.S. and other countries. The mortgage-backed securities and non-U.S. corporate and sovereign investments add further diversity to the fixed income portion of the portfolio.

Rate_Increases_Details

Rate Increases (Details) (PPUC [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Rate Request Filed on May 29, 2013 [Member] | Water [Member]
Rate Increases [Abstract]
Requested dollar increase in annual revenue	$7,116
Authorized dollar increase in annual revenue	4,972
Rate Request Filed on May 29, 2013 [Member] | Wastewater [Member]
Rate Increases [Abstract]
Requested dollar increase in annual revenue	28
Authorized dollar increase in annual revenue	28
DSIC [Member]
Rate Increases [Abstract]
Distribution system improvement charge revenue	$283	$1,445	$583
DSIC [Member] | Maximum [Member]
Rate Increases [Abstract]
Distribution system improvement charge percentage over base rate (in hundredths)	5.00%
DSIC [Member] | Minimum [Member]
Rate Increases [Abstract]
Distribution system improvement charge percentage over base rate (in hundredths)	0.00%

Notes_Receivable_and_Customers2

Notes Receivable and Customers' Advances for Construction (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Municipality
Notes Receivable and Customers' Advances for Construction [Abstract]
Number of municipalities with agreements to extend water service	3
Interest income on notes receivable	$107	$101	$98
Minimum interest rates on notes outstanding (in hundredths)	6.75%
Maximum interest rates on notes outstanding (in hundredths)	7.50%
Amounts related to water district projects included in balance sheet [Abstract]
Notes receivable, including interest	266	306
Customers' advances for construction	626	928
Other customers' advances for construction	$10,086	$10,708

Commitments_Details

Commitments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
	Employee
Commitments [Abstract]
Capital budget amount year one	$14,100
Capital budget amount year two	$15,800
Number of people employed	107
Number of people employed under union contract	38

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Interest Rate Swap [Abstract]
Term of debt on utilities rated A- used to discount prospective cash flows	30 years
Reduction in the fair value of swap liability	$75
Fair Value Estimate Not Practicable, Financial Liabilities [Abstract]
Customers' advances for construction	10,712	11,636
Fair Value Estimate Not Practicable, Financial Assets [Abstract]
Notes receivable	266	306
Fair Value, Estimate Not Practicable, Carrying Amount [Member]
Fair Value Estimate Not Practicable, Financial Liabilities [Abstract]
Customers' advances for construction	10,712	11,636
Fair Value Estimate Not Practicable, Financial Assets [Abstract]
Notes receivable	266	306
Carrying Amount [Member]
Fair Value, Financial Liabilities [Abstract]
Long-term debt (including current maturities)	84,885	84,928
Estimate of Fair Value [Member]
Fair Value, Financial Liabilities [Abstract]
Long-term debt (including current maturities)	100,000	94,000
Fair Value on a Recurring Basis [Member]
Interest Rate Swap [Abstract]
Interest rate swap	2,592	1,641
Fair Value on a Recurring Basis [Member] | Fair Value Measurements Using Significant Other Observable Inputs (Level 2) [Member]
Interest Rate Swap [Abstract]
Interest rate swap	$2,592	$1,641

Taxes_Other_than_Income_Taxes_1

Taxes Other than Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of Taxes Other than Income Taxes [Abstract]
Regulatory Assessment	$218	$220	$228
Property	339	364	342
Payroll, net of amounts capitalized	494	462	458
Capital Stock	59	75	151
Other	1	1	1
Total taxes other than income taxes	$1,111	$1,122	$1,180

Selected_Quarterly_Financial_D2

Selected Quarterly Financial Data (Unaudited) (Details) (USD $)	3 Months Ended									12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Abstract]
Operating revenues	$11,499		$12,062	$11,768	$10,571	$10,665	$10,912	$10,737	$10,069	$45,900	$42,383	$41,447
Operating income	5,427		6,092	5,800	4,758	5,320	5,367	5,301	4,773	22,077	20,761	20,573
Net income	3,551	[1]	3,065	2,757	2,111	2,638	2,535	2,342	2,139	11,484	9,654	9,303
Basic earnings per share (in dollars per share)	$0.28		$0.23	$0.22	$0.16	$0.21	$0.19	$0.18	$0.17	$0.89	$0.75	$0.72
Dividends declared per share (in dollars per share)	$0.15		$0.14	$0.14	$0.14	$0.14	$0.14	$0.14	$0.14	$0.58	$0.56	$0.54
IRS TPR ongoing deduction										($1,342)	$0	$0
[1]	Fourth quarter net income includes a tax benefit of $1,342 for the full year 2014 due to the implementation of the IRS tangible property regulations.

Schedule_II_Valuation_and_Qual1

Schedule II Valuation and Qualifying Accounts (Details) (Reserve for Uncollectible Accounts [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reserve for Uncollectible Accounts [Member]
Movement in Reserve [Roll Forward]
Balance at beginning of year	$320,000	$305,000	$333,681
Charged to cost and expenses	322,499	290,886	302,032
Recoveries	44,071	36,369	46,789
Deductions	361,570	312,255	377,502
Balance at end of year	$325,000	$320,000	$305,000