XML 24 R50.htm IDEA: XBRL DOCUMENT
v2.4.0.8

INVESTMENTS IN EQUITY INVESTEES - SCHEDULE OF COST METHOD INVESTMENTS (Details) (USD $) In Millions, unless otherwise specified | Sep. 30, 2012 OwnEnergy [Member] | Dec. 31, 2013 Two Dot Wind Project in Montana [Member] MW
--- | --- | ---
Schedule of Cost-method Investments [Line Items] |  |
Cost method investments | $ 8.8 | $ 22.0
Cost method investment, ownership percentage | 18.70% |
Number of megawatts |  | 9.7

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 Number of Megawatts + References No definition available. + Details
Name: | njr_NumberofMegawatts
Namespace Prefix: | njr_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | instant

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