Advances from customers for construction.

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- Definition

The maximum borrowing capacity for the construction loan as outlined in the closed agreement. Borrowings will take place when construction on a qualifying project is substantially complete.

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No definition available.

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The maximum borrowing amount for other loan sources not specifically stated in the taxonomy.

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No definition available.

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- Definition

Percentage of offering shares on discount to participants.

+ References

No definition available.

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- Definition

The percentage of the loan balance that is subject to the market interest rate at the time of closing in the contractual debt agreement.

+ References

No definition available.

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- Definition

The percentage of the loan balance that is subject to the stated interest rate in the contractual debt agreement.

+ References

No definition available.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount of long-term debt classified as other.

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- Definition

The cash inflow from amounts received from a long-term debt instrument secured by a first mortgage deed of trust, containing a pledge of real property. The lender has the highest claim on the property in case of default.

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- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Number of shares authorized for issuance under share-based payment arrangement.

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Number of shares issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity.

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Value of stock issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the holder of the stock to reinvest dividends paid to them by the entity on new issues of stock by the entity.

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Capitalization (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	May 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Jun. 30, 2019	Apr. 30, 2019	Feb. 28, 2019	Dec. 31, 2018	Sep. 30, 2018	Aug. 31, 2018	Apr. 30, 2018
Schedule of Capitalization [Line Items]
Issuance of shares under the DRP, shares		47,649
Issuance of shares under the DRP		$ 2,559	$ 286
Authorized shares under plan		1,500,000
Other long term debt		$ 67,600					$ 61,500
Customer advances		22,616					$ 22,572
Amount drawn		6,899	2,293
New Jersey NJIB Program [Member]
Schedule of Capitalization [Line Items]
Maximum borrowing amount			14,000
Maximum borrowing capacity, construction loan		$ 6,600						$ 8,700		$ 16,800
Delaware State Revolving Fund [Member]
Schedule of Capitalization [Line Items]
Maximum borrowing amount			$ 900					$ 10,000
Delaware State Revolving Fund [Member] \| Subsequent Event [Member]
Schedule of Capitalization [Line Items]
Maximum borrowing capacity, construction loan				$ 800	$ 1,700
Series 2018A [Member]
Schedule of Capitalization [Line Items]
Proceeds from issuance of first mortgage bond	$ 7,100
Interest rate	0.00%
Due date of debt	Aug. 01, 2047
Series 2018B [Member]
Schedule of Capitalization [Line Items]
Proceeds from issuance of first mortgage bond	$ 2,400
Due date of debt	Aug. 01, 2047
New Jersey Infrastructure Bank [Member]
Schedule of Capitalization [Line Items]
Maximum borrowing capacity, construction loan	$ 9,500					$ 140,000			$ 43,500	$ 55,000
Interest rate		0.00%
Percentage of principal with stated interest rate		75.00%
Percentage of principal with market interest rate		25.00%
Maximum [Member]
Schedule of Capitalization [Line Items]
Common stock granted and issued under plan		200,000
Percentage of offering shares on discount to participants		5.00%
Maximum [Member] \| Series 2018B [Member]
Schedule of Capitalization [Line Items]
Interest rate	5.00%
Minimum [Member] \| Series 2018B [Member]
Schedule of Capitalization [Line Items]
Interest rate	3.00%