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Organization, Summary of Significant Accounting Policies and Recent Developments (Schedule of Depreciation Rates) (Details) | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Source of Supply [Member] | Minimum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 1.15% | 1.15% | 1.15%
Source of Supply [Member] | Maximum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 3.44% | 3.44% | 3.44%
Pumping [Member] | Minimum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 2.87% | 2.87% | 2.87%
Pumping [Member] | Maximum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 5.39% | 5.39% | 5.39%
Water Treatment [Member] | Minimum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 1.65% | 1.65% | 1.65%
Water Treatment [Member] | Maximum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 7.09% | 7.09% | 7.09%
General Plant [Member] | Minimum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 2.08% | 2.08% | 2.08%
General Plant [Member] | Maximum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 17.84% | 17.84% | 17.84%
T&D Mains [Member] | Minimum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 1.10% | 1.10% | 1.10%
T&D Mains [Member] | Maximum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 3.13% | 3.13% | 3.13%
T&D Services [Member] | Minimum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 2.12% | 2.12% | 2.12%
T&D Services [Member] | Maximum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 3.16% | 3.16% | 3.16%
T&D Other [Member] | Minimum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 1.61% | 1.61% | 1.61%
T&D Other [Member] | Maximum [Member] |  |  |
Public Utility, Property, Plant and Equipment [Line Items] |  |  |
Public Utilities, Property, Plant and Equipment, Disclosure of Composite Depreciation Rate for Plants in Service | 4.63% | 4.63% | 4.63%

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