|**Taxes Other Than Income Taxes (Tables)**   | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
|-------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Taxes Other Than Income Taxes [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|Components Of Taxes Other Than Income Taxes  | ﻿﻿﻿
				
				Three Months Ended
				
				Six Months Ended﻿
				
				June 30,
				
				June 30,﻿
				
				2017
				
				2016
				
				2017
				
				2016﻿Property
				
				$
				6,867
				
				$
				6,928
				
				$
				13,652
				
				$
				13,113﻿Gross receipts, excise and franchise
				
				
				3,363
				
				
				3,113
				
				
				6,538
				
				
				6,059﻿Payroll
				
				
				2,132
				
				
				2,299
				
				
				5,256
				
				
				5,635﻿Regulatory assessments
				
				
				630
				
				
				681
				
				
				1,259
				
				
				1,352﻿Pumping fees
				
				
				1,350
				
				
				1,140
				
				
				2,294
				
				
				2,059﻿Other
				
				
				77
				
				
				81
				
				
				157
				
				
				164﻿Total taxes other than income
				
				$
				14,419
				
				$
				14,242
				
				$
				29,156
				
				$
				28,382﻿
		﻿
|﻿                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿Property                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿Gross receipts, excise and franchise        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿Payroll                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿Regulatory assessments                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿Pumping fees                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿Other                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿Total taxes other than income               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
|﻿                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

X- DefinitionTaxes Other than Income Taxes
+ ReferencesNo definition available.
+ Details**Name:**
wtr_TaxesOtherThanIncomeTaxesAbstract**Namespace Prefix:**
wtr_**Data Type:**
xbrli:stringItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionUtilities Operating Expenses, Taxes As In Annual Report [Table Text Block]
+ ReferencesNo definition available.
+ Details**Name:**
wtr_UtilitiesOperatingExpensesTaxesAsInAnnualReportTableTextBlock**Namespace Prefix:**
wtr_**Data Type:**
nonnum:textBlockItemType**Balance Type:**
na**Period Type:**
duration