| **Taxes Other Than Income Taxes (Tables)**   | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
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| **Taxes Other Than Income Taxes [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Components Of Taxes Other Than Income Taxes  |  

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

 

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

 

						 

Three Months Ended

						 

Nine Months Ended

 

						 

September 30,

						 

September 30,

 

						 

2015

						 

2014

						 

2015

						 

2014

Property

						 

$
6,945 				
						 

$
6,860 				
						 

$
20,776 				
						 

$
17,938 				
Capital stock

						 

						 
538 				
						 

						 
(274)				
						 

						 
1,619 				
						 

						 
749 				
Gross receipts, excise and franchise

						 

						 
2,859 				
						 

						 
2,727 				
						 

						 
7,855 				
						 

						 
8,476 				
Payroll

						 

						 
2,072 				
						 

						 
1,650 				
						 

						 
7,425 				
						 

						 
5,913 				
Regulatory assessments

						 

						 
693 				
						 

						 
694 				
						 

						 
2,033 				
						 

						 
1,877 				
Other 

						 

						 
1,556 				
						 

						 
1,158 				
						 

						 
3,371 				
						 

						 
2,990 				
Total taxes other than income

						 

$
14,663 				
						 

$
12,815 				
						 

$
43,079 				
						 

$
37,943 				
 

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

						 

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| - Definition
Taxes Other than Income Taxes
+ References
No definition available.
+ Details**Name:**wtr_TaxesOtherThanIncomeTaxesAbstract**Namespace Prefix:**wtr_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
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| - Definition
Utilities Operating Expenses, Taxes As In Annual Report [Table Text Block]
+ References
No definition available.
+ Details**Name:**wtr_UtilitiesOperatingExpensesTaxesAsInAnnualReportTableTextBlock**Namespace Prefix:**wtr_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |