XML 22 R28.htm IDEA: XBRL DOCUMENT v2.4.1.9

Commitments and Contingent Liabilities (Schedule of Purchased Water Costs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Purchased Water
Treated	$ 730msex_CostOfTreatedWater	$ 778msex_CostOfTreatedWater
Untreated	642msex_CostOfUntreatedWater	606msex_CostOfUntreatedWater
Total Costs	$ 1,372us-gaap_CostOfPurchasedWater	$ 1,384us-gaap_CostOfPurchasedWater

X

- Details

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

X

- Definition

Refers to cost of treated water during the period.

+ References

No definition available.

+ Details

Name:	msex_CostOfTreatedWater
Namespace Prefix:	msex_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Refers to cost of untreated water during the period.

+ References

No definition available.

+ Details

Name:	msex_CostOfUntreatedWater
Namespace Prefix:	msex_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Cost of water purchased, may include any water related assessment. If water is bought on a unit volume basis, would also be considered as commodity costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.2)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_CostOfPurchasedWater
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration