XML 61 R47.htm IDEA: XBRL DOCUMENT
v3.21.1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - NATURAL GAS IN STORAGE (Details) $ in Thousands | Mar. 31, 2021 USD ($) Bcf | Sep. 30, 2020 USD ($) Bcf
--- | --- | ---
Inventory [Line Items] |  |
Natural Gas in Storage, value | $ | $ 74,853 | $ 167,504
Natural Gas in Storage, Bcf | Bcf | 22.8 | 61.52
Natural Gas Distribution |  |
Inventory [Line Items] |  |
Natural Gas in Storage, value | $ | $ 40,083 | $ 110,037
Natural Gas in Storage, Bcf | Bcf | 9.4 | 27.2
Energy Services |  |
Inventory [Line Items] |  |
Natural Gas in Storage, value | $ | $ 34,439 | $ 57,352
Natural Gas in Storage, Bcf | Bcf | 13.3 | 34.3
Storage and Transportation |  |
Inventory [Line Items] |  |
Natural Gas in Storage, value | $ | $ 331 | $ 115
Natural Gas in Storage, Bcf | Bcf | 0.1 | 0.02

X
- Definition Natural Gas in Storage Nonmonetary Number of Billion Cubic Feet of Gas in Storage as of the balance sheet date. + References No definition available. + Details
Name: | njr_EnergyRelatedInventoryNaturalGasinStorageBCF
Namespace Prefix: | njr_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of natural gas in storage, which is a mixture of gases (liquefied or otherwise), used for fuel and manufacturing purposes, which is ready for sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.6(a)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_EnergyRelatedInventoryNaturalGasInStorage
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_InventoryLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=njr_NaturalGasDistributionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=njr_EnergyServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=njr_StorageAndTransportationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |