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Capitalization (Schedule of Carrying Amount and Fair Value of Bonds) (Details) - USD ($) $ in Thousands | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Carrying amount [Member] |  |
Bonds | $ 85,143 | $ 88,628
State Revolving Notes | 457 | 540
Fair value [Member] |  |
Bonds | 87,972 | 90,115
State Revolving Notes | $ 459 | $ 542

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- Definition Represents the aggregate of the first mortgage bonds reported on the balance sheet at period end measured at fair value by the entity. + References No definition available. + Details
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- Definition Represents the aggregate of the state revolving notes reported on the balance sheet at period end measured at fair value by the entity. + References No definition available. + Details
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Namespace Prefix: | msex_
Data Type: | xbrli:monetaryItemType
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- Details
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Namespace Prefix: |
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Balance Type: |
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |