XML 44 R40.htm IDEA: XBRL DOCUMENT
v2.4.1.9

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - LOAN RECEIVABLE (Details) (USD $) | 6 Months Ended |
--- | --- | ---
Mar. 31, 2015 | Sep. 30, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loans receivable in other current assets | $ 5,000,000us-gaap_FinancingReceivableRecordedInvestmentCurrent | $ 3,900,000us-gaap_FinancingReceivableRecordedInvestmentCurrent
Loans receivable in other noncurrent assets | 32,200,000us-gaap_NotesAndLoansReceivableGrossNoncurrent | 27,300,000us-gaap_NotesAndLoansReceivableGrossNoncurrent
Threshold period in establishing allowance for doubtful accounts | 60 days |
Allowance for doubtful accounts | $ 0us-gaap_AllowanceForDoubtfulAccountsReceivable | $ 0us-gaap_AllowanceForDoubtfulAccountsReceivable
Minimum [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loan term | 2 years |
Maximum [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Loan term | 10 years |

X
- Definition Allowance for Doubtful Accounts Receivable, Threshold Period + References No definition available. + Details
Name: | njr_AllowanceforDoubtfulAccountsReceivableThresholdPeriod
Namespace Prefix: | njr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loans Receivable Term + References No definition available. + Details
Name: | njr_LoansReceivableTerm
Namespace Prefix: | njr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5074-111524 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Financing receivables that are current. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition An amount representing an agreement for an unconditional promise by the maker to pay the Entity (holder) a definite sum of money at a future date(s) more than one year from the balance sheet date. Such amount may include accrued interest receivable in accordance with the terms of the debt. The debt also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. This amount does not include amounts related to receivables held-for-sale. + 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 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 + Details
Name: | us-gaap_NotesAndLoansReceivableGrossNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |