DERIVATIVE INSTRUMENTS (Tables)

6 Months Ended

Mar. 31, 2012

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Text Block]

The following table reflects the fair value of NJR's derivative assets and liabilities recognized in the Unaudited Condensed Consolidated Balance Sheets as of:

			Fair Value
			March 31, 2012						September 30, 2011
(Thousands)	Balance Sheet Location	Asset Derivatives			Liability Derivatives			Asset Derivatives			Liability Derivatives
Derivatives designated as hedging instruments:
NJRES:
Foreign currency contracts	Derivatives - current		$	127		$	22		$	153		$	8
	Derivatives - noncurrent		93			43			127			6
Fair value of derivatives designated as hedging instruments			$	220		$	65		$	280		$	14
Derivatives not designated as hedging instruments:
NJNG:
Financial commodity contracts	Derivatives - current		$	6,049		$	49,717		$	5,424		$	13,258
	Derivatives - noncurrent		163			—			2			620
NJRES:
Physical forward commodity contracts	Derivatives - current		21,541			11,150			33,240			10,570
	Derivatives - noncurrent		578			604			4,450			781
Financial commodity contracts	Derivatives - current		75,789			31,139			61,521			44,862
	Derivatives - noncurrent		2,499			3,104			1,936			4,934
Fair value of derivatives not designated as hedging instruments			$	106,619		$	95,714		$	106,573		$	75,025
Total fair value of derivatives			$	106,839		$	95,779		$	106,853		$	75,039

Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]

The following table reflects the effect of derivative instruments on the Unaudited Condensed Consolidated Statements of Operations as of:

(Thousands)	Location of gain (loss) recognized in income on derivatives	Amount of gain (loss) recognized in income on derivatives
		Three Months Ended					Six Months Ended
		March 31,					March 31,
Derivatives not designated as hedging instruments:		2012		2011			2012			2011
NJRES:
Physical commodity contracts	Operating revenues	$	8,745	$	41,306		$	(3,163	)	$	24,837
Physical commodity contracts	Gas purchases	116		(9,448		)	4,391			(5,739		)
Financial commodity contracts	Gas purchases	40,511		496			102,965			(27,775		)
Total unrealized and realized gains (losses)		$	49,372	$	32,354		$	104,193		$	(8,677	)

Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Text Block]

The following table reflect the effect of derivative instruments designated as cash flow hedges on OCI as of:

(Thousands)	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)					Amount of Gain or (Loss) Reclassified from OCI into Income (Effective Portion)						Amount of Gain or (Loss) Recognized on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)
	Three Months Ended					Three Months Ended						Three Months Ended
	March 31,					March 31,						March 31,
Derivatives in cash flow hedging relationships:	2012			2011		2012			2011			2012		2011
Foreign currency contracts	$	(25	)	$	42	$	(23	)	$	(50	)	$	—	$	—

(Thousands)	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) (1)					Amount of Gain or (Loss) Reclassified from OCI into Income (Effective Portion)						Amount of Gain or (Loss) Recognized on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)
	Six Months Ended					Six Months Ended						Six Months Ended
	March 31,					March 31,						March 31,
Derivatives in cash flow hedging relationships:	2012			2011		2012			2011			2012		2011
Foreign currency contracts	$	(75	)	$	161	$	(35	)	$	(59	)	$	—	$	—

(1) The settlement of foreign currency transactions over the next twelve months is expected to result in the reclassification of $105,000 from OCI into earnings. The maximum tenor is April 2015

Schedule of Derivative Instruments [Text Block]

NJNG and NJRES had the following outstanding long (short) derivatives as of:

		Volume (Bcf)
		March 31, 2012		September 30, 2011
NJNG	Futures	14.8		23.7
	Swaps	3.3		(1.8	)
	Options	2.4		1.1
NJRES	Futures	(26.0	)	(13.8	)
	Swaps	(0.7	)	(41.9	)
	Options	—		—
	Physical	24.6		58.3

Schedule of Due to (from) Broker-Dealers and Clearing Organizations [Text Block]

The Company maintains broker margin accounts for NJNG and NJRES. The balances by company, are as follows:

(Thousands)	Balance Sheet Location	March 31, 2012			September 30, 2011
NJNG	Broker margin - Current assets	$	46,361		$	11,722
NJRES	Broker margin - Current assets	$	20,154		$	10,873
NJRES	Broker margin - Current (liabilities)	$	(29,671	)	$	—

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

The amounts presented below have not been reduced by any collateral received or netting and exclude accounts receivable for NJNG retail natural gas sales and services.

(Thousands)	Gross Credit Exposure
Investment grade		$	107,085
Noninvestment grade		21,457
Internally rated investment grade		25,580
Internally rated noninvestment grade		7,451
Total		$	161,573