Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Total long-term debt	$ 6,034	$ 5,804
Less: current maturities	(53)	(24)
Total long-term debt due after one year	5,981	5,780
AmeriGas Propane
Debt Instrument [Line Items]
Unamortized debt issuance costs	(20)	(24)
Total long-term debt	2,560	2,565
AmeriGas Propane \| Other
Debt Instrument [Line Items]
Long-term debt, gross	$ 5	14
AmeriGas Propane \| Senior Notes \| 5.50% due May 2025
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	5.50%
Long-term debt, gross	$ 700	700
AmeriGas Propane \| Senior Notes \| 5.875% due August 2026
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	5.875%
Long-term debt, gross	$ 675	675
AmeriGas Propane \| Senior Notes \| 5.625% due May 2024
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	5.625%
Long-term debt, gross	$ 675	675
AmeriGas Propane \| Senior Notes \| 5.75% due May 2027
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	5.75%
Long-term debt, gross	$ 525	525
UGI International
Debt Instrument [Line Items]
Unamortized debt issuance costs	(7)	(8)
Total long-term debt	$ 778	719
UGI International \| Senior Notes \| 3.25% Senior Notes due November 2025
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	3.25%
Long-term debt, gross	$ 410	382
UGI International \| Term Loan \| Variable-rate term loan
Debt Instrument [Line Items]
Long-term debt, gross	352	327
Other
Debt Instrument [Line Items]
Total long-term debt	8	8
Other \| Other \| Other
Debt Instrument [Line Items]
Long-term debt, gross	23	18
Midstream & Marketing:
Debt Instrument [Line Items]
Unamortized debt issuance costs	(12)	(12)
Total long-term debt	720	687
Midstream & Marketing: \| Other \| Other
Debt Instrument [Line Items]
Long-term debt, gross	41	1
Midstream & Marketing: \| Term Loan \| Variable-rate term loan
Debt Instrument [Line Items]
Long-term debt, gross	691	698
UGI Utilities
Debt Instrument [Line Items]
Unamortized debt issuance costs	(5)	(5)
Total long-term debt	$ 1,121	979
UGI Utilities \| Senior Notes \| 4.12%, due September 2046
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	4.12%
Long-term debt, gross	$ 200	200
UGI Utilities \| Senior Notes \| 4.98%, due March 2044
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	4.98%
Long-term debt, gross	$ 175	175
UGI Utilities \| Senior Notes \| 3.12% due April 2050
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	3.12%
Long-term debt, gross	$ 150	0
UGI Utilities \| Senior Notes \| 4.55%, due February 2049
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	4.55%
Long-term debt, gross	$ 150	150
UGI Utilities \| Senior Notes \| 4.12%, due October 2046
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	4.12%
Long-term debt, gross	$ 100	100
UGI Utilities \| Senior Notes \| 6.21%, due September 2036
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	6.21%
Long-term debt, gross	$ 100	100
UGI Utilities \| Senior Notes \| 2.95%, due June 2026
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	2.95%
Long-term debt, gross	$ 100	100
UGI Utilities \| Other \| Other
Debt Instrument [Line Items]
Long-term debt, gross	3	5
UGI Utilities \| Term Loan \| Variable-rate term loan
Debt Instrument [Line Items]
Long-term debt, gross	$ 108	114
UGI Utilities \| Medium-term Notes \| 6.13%, due October 2034
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	6.13%
Long-term debt, gross	$ 20	20
UGI Utilities \| Medium-term Notes \| 6.50%, due August 2033
Debt Instrument [Line Items]
Stated interest rate (as a percentage)	6.50%
Long-term debt, gross	$ 20	20
UGI Coporation
Debt Instrument [Line Items]
Unamortized debt issuance costs	(3)	(4)
Total long-term debt	847	846
UGI Coporation \| Term Loan \| 3-year Term loan
Debt Instrument [Line Items]
Long-term debt, gross	300	300
UGI Coporation \| Term Loan \| 5-year Term Loan
Debt Instrument [Line Items]
Long-term debt, gross	250	250
UGI Coporation \| Line of Credit
Debt Instrument [Line Items]
Long-term debt, gross	$ 300	$ 300

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.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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