Summary of Significant Accounting Policies - (Narrative) (Details) $ in Millions	Dec. 31, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease ROU assets	$ 429.6
Lease Liabilities	429.6
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease ROU assets	451.9
Lease Liabilities	$ 451.9
Southern Company \| PennEast Pipeline Company, LLC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity method investment ownership percent	20.00%
New Jersey Resources \| PennEast Pipeline Company, LLC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity method investment ownership percent	20.00%
South Jersey Industries \| PennEast Pipeline Company, LLC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity method investment ownership percent	20.00%
Enbridge Inc \| PennEast Pipeline Company, LLC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity method investment ownership percent	20.00%
Affiliated Entity \| UGI PennEast, LLC \| PennEast Pipeline Company, LLC
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity method investment ownership percent	20.00%

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
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Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
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