SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

3 Months Ended

Dec. 31, 2011

Accounting Policies [Abstract]

Derivatives, Policy [Text Block]

The Company and certain of its subsidiaries are subject to commodity price risk due to fluctuations in the market price of natural gas. To manage this risk, the Company and certain of its subsidiaries enter into a variety of derivative instruments including, but not limited to, futures contracts, physical forward contracts, financial options and swaps to economically hedge the commodity price risk associated with its existing and anticipated commitments to purchase and sell natural gas. In addition, the Company may utilize foreign currency derivatives as cash flow hedges of Canadian dollar denominated gas purchases. These contracts, with a few exceptions as described below, are accounted for as derivatives. Accordingly, all of the financial and certain of the Company's physical derivative instruments are recorded at fair value in the Unaudited Condensed Consolidated Balance Sheets. For a more detailed discussion of the Company's fair value measurement policies and level disclosures associated with the NJR's derivative instruments. See Note 5. Fair Value.

Since the Company chooses not to designate its financial commodity and physical forward commodity derivatives as accounting hedges, changes in the fair value of these derivative instruments are recorded as a component of gas purchases or operating revenues, as appropriate for NJRES, in the Unaudited Condensed Consolidated Statements of Operations as unrealized gains or (losses). For NJRES at settlement, realized gains and (losses) on all financial derivative instruments are recognized as a component of gas purchases and realized gains and (losses) on all physical derivatives follow the presentation of the related unrealized gains and (losses) as a component of either gas purchases or operating revenues.

NJRES also enters into natural gas transactions in Canada and, consequently, is exposed to fluctuations in the value of Canadian currency relative to the US dollar. NJRES utilizes foreign currency derivatives to lock in the currency translation rate associated with natural gas transactions denominated in Canadian currency. The derivatives may include currency forwards, futures, or swaps and are accounted for as derivatives. These derivatives are being used to hedge future forecasted cash payments associated with transportation and storage contracts. The Company has designated these foreign currency derivatives as cash flow hedges of that exposure, and expects the hedge relationship to be highly effective throughout the term. Since NJRES designates its foreign exchange contracts as cash flow hedges, changes in fair value of the effective portion of the hedge are recorded in other comprehensive income (OCI). When the foreign exchange contracts are settled, realized gains and (losses) are recognized in gas purchases in the Unaudited Condensed Consolidated Statements of Operations.

As a result of NJRES entering into transactions to borrow gas, commonly referred to as “park and loans,” an embedded derivative is created related to potential differences between the fair value of the amount borrowed and the fair value of the amount that may ultimately be repaid, based on changes in forward natural gas prices during the contract term. This embedded derivative is accounted for as a forward sale in the month in which the repayment of the borrowed gas is expected to occur, and is considered a derivative transaction that is recorded at fair value in the Unaudited Condensed Consolidated Balance Sheets, with changes in value recognized in current period earnings.

Changes in fair value of NJNG's financial derivative instruments are recorded as a component of regulatory assets or liabilities in the Unaudited Condensed Consolidated Balance Sheets, as NJNG has received regulatory approval to defer and to recover these amounts through future BGSS rates as an increase or decrease to the cost of natural gas in NJNG's tariff.

The Company elects normal purchase/normal sale accounting treatment on all physical commodity contracts at NJNG. These contracts are accounted for on an accrual basis. Accordingly, gains or (losses) are recognized in earnings when the contract settles and the natural gas is delivered.

Marketable Securities, Available-for-sale Securities, Policy [Policy Text Block]

Available for Sale Securities

Included in other noncurrent assets on the Unaudited Condensed Consolidated Balance Sheets are certain investments in equity securities of a publicly traded energy company that have a fair value of $11.8 million and $10.3 million as of December 31, 2011 and September 30, 2011, respectively. Total unrealized gains associated with these equity securities, which are included as a part of accumulated other comprehensive income, a component of common stock equity, were $9.1 million ($5.4 million, after tax) and $7.7 million ($4.5 million, after tax) as of December 31, 2011 and September 30, 2011, respectively.

Asset Retirement Obligations, Policy [Policy Text Block]

Asset Retirement Obligations (ARO)

NJR recognizes AROs related to the costs associated with cutting and capping its main and service gas distribution pipelines of NJNG, which are required by New Jersey law when taking such gas distribution pipeline out of service.

The following is an analysis of the change in the ARO liability for the three months endedDecember 31, 2011 and the twelve months ended September 30, 2011:

(Thousands)	December 31, 2011			September 30, 2011
Balance at October 1	$	27,026		$	26,009
Accretion	440			1,663
Additions	—			180
Retirements	(341		)	(826		)
Balance at period end	$	27,125		$	27,026

Accretion amounts are not reflected as an expense on NJR's Unaudited Condensed Consolidated Statements of Operations, but rather are deferred as a regulatory asset and netted against NJNG's regulatory liabilities, for presentation purposes, on the Unaudited Condensed Consolidated Balance Sheets.

Fair Value of Financial Instruments, Policy [Policy Text Block]

Fair Value Hierarchy

NJR applies fair value measurement guidance to its financial assets and liabilities, as appropriate, which include financial derivatives and physical commodity contracts qualifying as derivatives, available for sale securities and other financial assets and liabilities. In addition, authoritative accounting literature prescribes the use of a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value based on the source of the data used to develop the price inputs. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to inputs that are based on unobservable market data and include the following:

Level 1 Unadjusted quoted prices for identical assets or liabilities in active markets; NJR's Level 1 assets and liabilities include exchange traded futures contracts, listed equities, and money market funds.

Level 2 Price data, which includes both commodity and basis price data other than Level 1 quotes, that is observed either directly or indirectly from publications or pricing services; NJR's Level 2 assets and liabilities include over-the-counter physical forward commodity contracts and swap contracts or derivatives that are initially valued using observable quotes and are subsequently adjusted to include time value, credit risk or estimated transport pricing components for which no basis price is available. These additional adjustments are not considered significant to the ultimate recognized values.

Level 3 Inputs derived from a significant amount of unobservable market data; these include NJR's best estimate of fair value and are derived primarily through the use of internal valuation methodologies.

NJNG's and NJRES' financial derivatives portfolios consist mainly of futures, options and swaps. NJR primarily uses the market approach and its policy is to use actively quoted market prices when available. The principal market for its derivative transactions is the natural gas wholesale market, therefore, the primary source for its price inputs is the New York Mercantile (NYMEX) exchange. NJRES also uses Natural Gas Exchange (NGX) for Canadian delivery points and Platts and NYMEX ClearPort for certain over-the-counter physical forward commodity contracts. However, NJRES also engages in transactions that result in transporting natural gas to delivery points for which there is no actively quoted market price. In most instances, the cost to transport to the final delivery location is not significant to the overall valuation. If required, NJRES' policy is to use the best information available to determine fair value based on internal pricing models, which would include estimates extrapolated from broker quotes or pricing services.

NJR also has available for sale securities and other financial assets that include listed equities, mutual funds and money market funds for which there are active exchange quotes available.

When NJR determines fair values, measurements are adjusted, as needed, for credit risk associated with its counterparties, as well as its own credit risk. NJR determines these adjustments by using historical default probabilities that correspond to the applicable Standard and Poor's issuer ratings, while also taking into consideration collateral and netting arrangements that serve to mitigate risk.