XML 35 R23.htm IDEA: XBRL DOCUMENT v3.5.0.2

Basis of Presentation and Recent Developments (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($)
Basis of Presentation and Recent Developments [Abstract]
Reclassification due to new accounting standard	$ (3,300)

X

- Definition

Basis Of Presentation And Recent Developments [Abstract ].

+ References

No definition available.

+ Details

Name:	msex_BasisOfPresentationAndRecentDevelopmentsAbstract
Namespace Prefix:	msex_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of unamortized debt expense that was reclassified from assets to long-term debt during the period due to the adoption of new accounting standards.

+ References

No definition available.

+ Details

Name:	msex_ReclassificationOfUnamortizedDebtExpenseDueToNewAccountingStandard
Namespace Prefix:	msex_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration