XML 45 R45.htm IDEA: XBRL DOCUMENT
v2.4.1.9

DERIVATIVE INSTRUMENTS - VOLUME (Details) | Dec. 31, 2014 MMcf | Sep. 30, 2014 MMcf
--- | --- | ---
NJNG [Member] | Futures [Member] | Long [Member] |  |
Derivative [Line Items] |  |
Derivative, nonmonetary notional amount | 21,500 invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_FutureMember / dei_LegalEntityAxis = njr_NjngMember / us-gaap_PositionAxis = us-gaap_LongMember | 17,300 invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_FutureMember / dei_LegalEntityAxis = njr_NjngMember / us-gaap_PositionAxis = us-gaap_LongMember
NJNG [Member] | Options [Member] | Long [Member] |  |
Derivative [Line Items] |  |
Derivative, nonmonetary notional amount | 500 invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_OptionMember / dei_LegalEntityAxis = njr_NjngMember / us-gaap_PositionAxis = us-gaap_LongMember | 0 invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_OptionMember / dei_LegalEntityAxis = njr_NjngMember / us-gaap_PositionAxis = us-gaap_LongMember
NJRES [Member] | Futures [Member] | Short [Member] |  |
Derivative [Line Items] |  |
Derivative, nonmonetary notional amount | (83,200)invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_FutureMember / dei_LegalEntityAxis = njr_NjresMember / us-gaap_PositionAxis = us-gaap_ShortMember | (62,100)invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_FutureMember / dei_LegalEntityAxis = njr_NjresMember / us-gaap_PositionAxis = us-gaap_ShortMember
NJRES [Member] | Options [Member] | Long [Member] |  |
Derivative [Line Items] |  |
Derivative, nonmonetary notional amount | 1,200 invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_OptionMember / dei_LegalEntityAxis = njr_NjresMember / us-gaap_PositionAxis = us-gaap_LongMember | 1,200 invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_OptionMember / dei_LegalEntityAxis = njr_NjresMember / us-gaap_PositionAxis = us-gaap_LongMember
NJRES [Member] | Physical [Member] | Long [Member] |  |
Derivative [Line Items] |  |
Derivative, nonmonetary notional amount | 67,600 invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_ForwardContractsMember / dei_LegalEntityAxis = njr_NjresMember / us-gaap_PositionAxis = us-gaap_LongMember | 28,600 invest_DerivativeNonmonetaryNotionalAmount / us-gaap_DerivativeByNatureAxis = us-gaap_ForwardContractsMember / dei_LegalEntityAxis = njr_NjresMember / us-gaap_PositionAxis = us-gaap_LongMember

X
- Definition Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
Name: | invest_DerivativeNonmonetaryNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

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

X
- Details
Name: | dei_LegalEntityAxis=njr_NjngMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=njr_NjresMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |