XML 82 R61.htm IDEA: XBRL DOCUMENT
v3.10.0.1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - RECENTLY ADOPTED ACCOUNTING STANDARDS (Details) - USD ($) $ in Thousands | 12 Months Ended |  |  |
--- | --- | --- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2015
Accounting Policies [Abstract] |  |  |  |  |
Reclassifications of certain income tax effects to retained earnings | [1] | $ 3,300 |  |  |
Equity reclass |  | 1,418,978 | $ 1,236,643 | $ 1,166,591 | $ 1,106,956
Deferred gain, unamortized balance |  | $ (6,800) |  |  |
[1] | Due to the adoption of ASU No. 2018-02, an amendment to ASC 740, Income Taxes. See Note 2. Summary of Significant Accounting Policies - Recently Adopted Updates to the Accounting Standards Codification section for more details.

X
- Definition Deferred Gain (Loss), Unamortized Amount + References No definition available. + Details
Name: | njr_DeferredGainLossUnamortizedAmount
Namespace Prefix: | njr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings, Tax Effect + References No definition available. + Details
Name: | njr_TaxCutsandJobsActof2017ReclassificationfromAOCItoRetainedEarningsTaxEffect
Namespace Prefix: | njr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 4.E) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707 Reference 2: 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(31)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: 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(30)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockholdersEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant