Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=ugi_UGIInternationalCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ugi_FlagaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ugi_FlagaTermLoanDueSeptemberTwentyEighteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=ugi_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_VariableRateAxis=ugi_EURIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Debt - UGI International (Details) $ in Millions	1 Months Ended
Debt - UGI International (Details) $ in Millions	Dec. 31, 2017 USD ($)	Sep. 30, 2018 EUR (€)	Sep. 30, 2018 USD ($)	Dec. 31, 2017 EUR (€)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 EUR (€)	Sep. 30, 2017 USD ($)
UGI International Credit Agreement \| Line of Credit \| Revolving Credit Facility
Debt Instrument
Total capacity \| €				€ 300,000,000
Flaga
Debt Instrument
Total capacity \| €		€ 55,000,000				€ 55,000,000
Flaga \| Flaga Term Loan, due September 2018 \| Term Loan
Debt Instrument
Repayments of debt \| $	$ 9.2
Long-term debt, gross \| $			$ 49.9		$ 59.1		$ 59.1
Minimum \| EURIBOR \| UGI International Credit Agreement \| Line of Credit \| Revolving Credit Facility
Debt Instrument
Basis spread on variable rate (percentage)	1.45%
Minimum \| London Interbank Offered Rate (LIBOR) \| UGI International Credit Agreement \| Line of Credit \| Revolving Credit Facility
Debt Instrument
Basis spread on variable rate (percentage)	1.70%
Minimum \| London Interbank Offered Rate (LIBOR) \| Flaga \| Flaga Term Loan, due September 2018 \| Term Loan
Debt Instrument
Basis spread on variable rate (percentage)	1.125%
Maximum \| EURIBOR \| UGI International Credit Agreement \| Line of Credit \| Revolving Credit Facility
Debt Instrument
Basis spread on variable rate (percentage)	2.35%
Maximum \| London Interbank Offered Rate (LIBOR) \| UGI International Credit Agreement \| Line of Credit \| Revolving Credit Facility
Debt Instrument
Basis spread on variable rate (percentage)	2.60%