XML 70 R68.htm IDEA: XBRL DOCUMENT v2.4.0.8

INVESTMENTS IN EQUITY INVESTEES, COST METHOD INVESTMENTS (Details) (USD $)	12 Months Ended							3 Months Ended	1 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Wind Purchase Option [Member]	Oct. 09, 2014 Alexander Wind Project in Kansas [Member] Subsequent Event [Member] MWh	Sep. 30, 2014 Carroll Wind Project in Iowa [Member] MWh	Sep. 30, 2014 Two Dot Wind Project in Montana [Member] MWh	Sep. 30, 2012 OwnEnergy [Member]	Sep. 30, 2014 PennEast [Member] Investor mi	Oct. 31, 2014 PennEast [Member] Subsequent Event [Member] Investor
Schedule of Cost-method Investments [Line Items]
Number of other investors which formed PennEast								4	6
Construction plan, pipeline distance (in miles)								108
Cost method investments							$ 8,800,000
Cost method investment, ownership percentage							18.70%
Number of megawatts of the wind project				48	20	9.7
Solar and wind equipment, real estate properties and other, at cost	347,285,000	249,516,000	(2,400,000)
Asset impairment loss	6,400,000
Asset impairment loss, after tax	3,800,000
Development project costs				$ 85,000,000	$ 42,000,000	$ 21,200,000

X

- Definition

Asset Impairment Charges, net

+ References

No definition available.

+ Details

Name:	njr_AssetImpairmentChargesnet
Namespace Prefix:	njr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Construction Plan, Project Area

+ References

No definition available.

+ Details

Name:	njr_ConstructionPlanProjectArea
Namespace Prefix:	njr_
Data Type:	num:lengthItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The percentage of ownership of common stock or equity in the investee accounted for under the cost method of accounting.

+ References

No definition available.

+ Details

Name:	njr_CostMethodInvestmentOwnershipPercentage
Namespace Prefix:	njr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Development Project Costs

+ References

No definition available.

+ Details

Name:	njr_DevelopmentProjectCosts
Namespace Prefix:	njr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Number of Investors

+ References

No definition available.

+ Details

Name:	njr_NumberofInvestors
Namespace Prefix:	njr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of Megawatts

+ References

No definition available.

+ Details

Name:	njr_NumberofMegawatts
Namespace Prefix:	njr_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228

+ Details

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

X

- Definition

Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.12)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6872867&loc=d3e40691-111596



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 20

-Section 35

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=29638308&loc=d3e40346-111594

+ Details

Name:	us-gaap_CostMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount before accumulated depreciation, depletion and amortization of other physical assets used in the normal conduct of business to produce goods and services and not intended for resale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_ScheduleOfCostMethodInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration