Employee Retirement Plans - Pension Plans Assets (Details) - Pension Benefits - U.S.	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans
Actual	100.00%	100.00%
Target Asset Allocation	100.00%	100.00%
Target allocation range	5.00%
U.S. equities
Defined Benefit Plans and Other Postretirement Benefit Plans
Actual	26.50%	22.20%
Target Asset Allocation	24.70%	25.30%
Non-U.S. equities
Defined Benefit Plans and Other Postretirement Benefit Plans
Actual	20.90%	21.70%
Target Asset Allocation	20.90%	21.40%
Global equities
Defined Benefit Plans and Other Postretirement Benefit Plans
Actual	13.80%	16.00%
Target Asset Allocation	13.10%	13.10%
Equity investments
Defined Benefit Plans and Other Postretirement Benefit Plans
Actual	61.20%	59.90%
Target Asset Allocation	58.70%	59.80%
Fixed income funds & cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans
Actual	35.50%	36.40%
Target Asset Allocation	35.00%	34.40%
Alternative investments
Defined Benefit Plans and Other Postretirement Benefit Plans
Actual	3.30%	3.70%
Target Asset Allocation	6.30%	5.80%

Defined Benefit Plan, Plan Assets, Target Allocation Range, Percentage

No definition available.

Name:	ugi_DefinedBenefitPlanPlanAssetsTargetAllocationRangePercentage
Namespace Prefix:	ugi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DefinedBenefitPlanEquitySecuritiesUsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DefinedBenefitPlanEquitySecuritiesNonUsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=ugi_DefinedBenefitPlanEquitySecuritiesUSNonUSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=ugi_FixedIncomeFundsAndCashEquivalentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=ugi_AlternativeInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: