Debt Instrument, Multiplier of Variable Rate

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- Definition

Interest rate stated in the contractual debt agreement.

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-Name Regulation S-X (SX)

-Number 210

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- Definition

When presenting a range of interest rates, the highest stated (contractual) rate for funds borrowed under the debt agreement as of the balance sheet date.

+ References

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When presenting a range of interest rates, the lowest stated (contractual) rate for funds borrowed under the debt agreement as of the balance sheet date.

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-Name Regulation S-X (SX)

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- Definition

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

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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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Reflects the calculation as of the balance sheet date of the average interest rate weighted by the amount of debt outstanding by type or by instrument at that time.

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- Definition

The interest portion of minimum lease payments required under transactions involving the sale of property to another party and the lease of the property back to the seller accounted for as capital leases, under the deposit method, or as a financing that represents the finance cost of the arrangement.

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Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date. May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

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Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date.

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-Subparagraph (SX 210.5-02.22)

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Total of the portions of the carrying amounts as of the balance sheet date of long-term debt, which may include notes payable, bonds payable, debentures, mortgage loans, and commercial paper, which are scheduled to be repaid within one year or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

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Amount of long-term debt maturities after year five following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

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Amount of long-term debt maturing within the next twelve months following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates.

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Amount of long-term debt maturing in year five following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

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Amount of long-term debt maturing in year four following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

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Amount of long-term debt maturing in year three following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed of determinable prices and dates.

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Amount of long-term debt maturing in year two following the date of the latest balance sheet presented in the financial statements, which may include maturities of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates.

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The total future minimum lease payments as of the date of the latest balance sheet presented, with separate deductions from the total for the amount representing executory costs, including any profit thereon, required under all transactions involving the sale of property to another party and the lease of the property back to the seller.

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The future minimum lease payments as of the date of the latest balance sheet presented, with separate deductions from the total for the amount representing executory costs, including any profit thereon, required under all transactions involving the sale of property to another party and the lease of the property back to the seller, which payments are due after the fifth year following the balance sheet date.

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The future minimum lease payments as of the date of the latest balance sheet presented, with separate deductions from the total for the amount representing executory costs, including any profit thereon, required under all transactions involving the sale of property to another party and the lease of the property back to the seller, which payments are due in the fifth year following the balance sheet date.

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The future minimum lease payments as of the date of the latest balance sheet presented, with separate deductions from the total for the amount representing executory costs, including any profit thereon, required under all transactions involving the sale of property to another party and the lease of the property back to the seller, which payments are due in the fourth year following the balance sheet date.

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The future minimum lease payments as of the date of the latest balance sheet presented, with separate deductions from the total for the amount representing executory costs, including any profit thereon, required under all transactions involving the sale of property to another party and the lease of the property back to the seller, which payments are due in the third year following the balance sheet date.

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The future minimum lease payments as of the date of the latest balance sheet presented, with separate deductions from the total for the amount representing executory costs, including any profit thereon, required under all transactions involving the sale of property to another party and the lease of the property back to the seller, which payments are due in the second year following the balance sheet date.

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The total of all minimum lease payments required under all transactions involving the sale of property to another party and the lease of the property back to the seller accounted for as capital leases, under the deposit method, or as a financing less the portion that will be accounted for as interest expense.

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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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

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-Paragraph 14

-Subparagraph (b)

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-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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The cash outflow from the repayment of a long-term debt instrument issued, 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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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

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- Definition

A segregation of retained earnings which is unavailable for dividend distribution. Includes also retained earnings appropriated for loss contingencies.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

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-Paragraph 1

-Subparagraph (SX 210.5-02.30(a)(3)(i))

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-Name Regulation S-X (SX)

-Number 210

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-Article 5

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-Number 210

-Article 7

-Section 03

-Paragraph 24

-Subparagraph a(4)

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The gross proceeds received from the asset(s) sold in connection with the transaction involving the sale of property to another party and the lease back to the seller.

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

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-Topic 840

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DEBT, SCHEDULE OF LONG TERM DEBT (Details) (USD $)	3 Months Ended	12 Months Ended
DEBT, SCHEDULE OF LONG TERM DEBT (Details) (USD $)	Sep. 30, 2011	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt		$ 97,045,000	$ 0	$ 0
Repayments of Long-term Debt		130,091,000	6,749,000	60,362,000
Long-term debt	426,797,000	426,797,000	428,925,000
Long-term Debt, by Maturity [Abstract]
2012	0	0
2013	0	0
2014	60,000,000	60,000,000
2015	0	0
2016	0	0
Thereafter	319,800,000	319,800,000
NJNG [Member] \| Interest Rate I [Member] \| Debt, Auction Rate Securities [Member]
Debt Instrument [Line Items]
Debt Instrument, Multiplier of Variable Rate		175.00%
NJNG [Member] \| Interest Rate II [Member] \| Debt, Auction Rate Securities [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum		10.00%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum		12.00%
Debt, Auction Rate Securities [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt		97,045,000
NJNG [Member] \| Series AA [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	0	0	25,000,000
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Series BB [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	0	0	16,000,000
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Series CC [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	0	0	20,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.88%	6.88%
Redemption of First Mortgage Bond		20,000,000
NJNG [Member] \| Series DD [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	0	0	13,500,000
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Series EE [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	0	0	9,545,000
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Series FF [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	0	0	15,000,000
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Series GG [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	0	0	18,000,000
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Series HH [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	12,000,000	12,000,000	12,000,000
Debt Instrument, Interest Rate, Stated Percentage	5.00%	5.00%
NJNG [Member] \| Series II [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	10,300,000	10,300,000	10,300,000
Debt Instrument, Interest Rate, Stated Percentage	4.50%	4.50%
NJNG [Member] \| Series JJ [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	10,500,000	10,500,000	10,500,000
Debt Instrument, Interest Rate, Stated Percentage	4.60%	4.60%
NJNG [Member] \| Series KK [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	15,000,000	15,000,000	15,000,000
Debt Instrument, Interest Rate, Stated Percentage	4.90%	4.90%
NJNG [Member] \| Series LL [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	125,000,000	125,000,000	125,000,000
Debt Instrument, Interest Rate, Stated Percentage	5.60%	5.60%
Variable Demand Rate Notes [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt		97,045,000
NJNG [Member] \| Series MM [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	9,545,000	9,545,000	0
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Series NN [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	41,000,000	41,000,000	0
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Series OO [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Long-term Debt	46,500,000	46,500,000	0
Debt Instrument, Interest Rate Terms		Variable
NJNG [Member] \| Capital lease obligation-Buildings [Member] \| Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt	23,314,000	23,314,000	24,611,000
NJNG [Member] \| Capital lease obligation-Meters [Member] \| Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt	30,683,000	30,683,000	34,962,000
NJNG [Member] \| Capital lease obligation-Equipment [Member] \| Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt	530,000	530,000	764,000
First Mortgage [Member]
Debt Instrument [Line Items]
Retained Earnings, Appropriated	288,000,000	288,000,000
NJR [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term Debt	50,000,000	50,000,000	50,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.05%	6.05%
NJNG [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Long-term Debt	60,000,000	60,000,000	60,000,000
Debt Instrument, Interest Rate, Stated Percentage	4.77%	4.77%
NJR [Member]
Debt Instrument [Line Items]
Long-term debt	50,000,000	50,000,000	50,000,000
Present Value of Future Minimum Lease Payments, Sale Leaseback Transactions [Abstract]
2012	9,500,000	9,500,000
2013	9,900,000	9,900,000
2014	9,000,000	9,000,000
2015	8,900,000	8,900,000
2016	9,500,000	9,500,000
Thereafter	23,100,000	23,100,000
Subtotal	69,900,000	69,900,000
Less: interest component	(15,400,000)	(15,400,000)
Total	54,500,000	54,500,000
NJNG [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum		12.00%
Debt Weighted Average Interest Rate	0.16%	0.16%
Long-term Debt, Current Maturities	(7,575,000)	(7,575,000)	(31,257,000)
Long-term debt	376,797,000	376,797,000	378,925,000
Sale Leaseback Transaction, Gross Proceeds	$ 3,900,000	$ 5,900,000	$ 4,900,000	$ 6,300,000