|**Acquisitions**            | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
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|**Acquisitions [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|Acquisitions                | Note 4 –Acquisitions
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		During the first six months of 2018, the Company completedthreeacquisitions of water and wastewater utility systems in various states adding448customers.  The total purchase price of these utility systems consisted of$190in cash.  The purchase price allocation for these acquisitions consisted primarily of acquired property, plant and equipment.  The pro forma effect of the businesses acquired is not material either individually or collectively to the Company’s results of operations.
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		In July 2018, the Company entered into a purchase agreement to acquire the wastewater utility system assets of Cheltenham Township, Pennsylvania, which serves approximately10,500customers for$50,250.  The purchase price for this pending acquisition is subject to certain adjustments at closing, and is subject to regulatory approval, including the final determination of the fair value of the rate base acquired.
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		In addition to the Company’s pending acquisition in Cheltenham Township, Pennsylvania, as part of the Company’s growth-through-acquisition strategy, the Company entered into purchase agreements to acquire the water or wastewater utility system assets ofsevenmunicipalities for a total combined purchase price in cash of$152,800, which we plan to finance by the issuance of debt.  The purchase price for these acquisitions is subject to certain adjustments at closing, and the acquisitions are subject to regulatory approvals, including the final determination of the fair value of the rate base acquired.  In July 2018, we closed on the following acquisitions:
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		·Manteno, Illinois for$25,000in cash, which serves approximately3,800wastewater customers, and
		·Limerick, Pennsylvania for$75,100in cash, which serves approximately5,400wastewater customers.
		
		Closings for our remaining acquisitions are expected to occur by the end of 2019, subject to the timing of the regulatory approval process.  In total, these acquisitions will add approximately16,750customers intwoof the states in which the Company operates in.
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		During 2017, the Company completed four acquisitions of water and wastewater utility systems in various states adding1,003customers.  The total purchase price of these utility systems consisted of$5,860in cash, which resulted in$72of goodwill being recorded.  The pro forma effect of the businesses acquired is not material either individually or collectively to the Company’s results of operations.
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X- DefinitionThe entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).
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