Nature of Operations	6 Months Ended
Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Note 1 — Nature of Operations UGI is a holding company that, through subsidiaries and affiliates, distributes, stores, transports and markets energy products and related services. In the United States, we (1) are the general partner and own limited partner interests in a retail propane marketing and distribution business; (2) own and operate natural gas and electric distribution utilities; and (3) own and operate an energy marketing, midstream infrastructure, storage, natural gas gathering, natural gas production, electricity generation and energy services business. In Europe, we market and distribute propane and other LPG and market energy products and services. We conduct a domestic propane marketing and distribution business through AmeriGas Partners. AmeriGas Partners is a publicly traded limited partnership that conducts a national propane distribution business through its principal operating subsidiary, AmeriGas OLP. AmeriGas Partners and AmeriGas OLP are Delaware limited partnerships. UGI’s wholly owned second-tier subsidiary, AmeriGas Propane, Inc., serves as the General Partner of AmeriGas Partners and AmeriGas OLP. At March 31, 2019, the General Partner held a 1% general partner interest and a 25.3% limited partner interest in AmeriGas Partners and held an effective 27.0% ownership interest in AmeriGas OLP. Our limited partnership interest in AmeriGas Partners comprises Common Units. The remaining 73.7% interest in AmeriGas Partners comprises Common Units held by the public. The General Partner also holds incentive distribution rights that entitle it to receive distributions from AmeriGas Partners in excess of its 1% general partner interest under certain circumstances as further described in Note 14 of the Company’s 2018 Annual Report. Incentive distributions received by the General Partner during the six months ended March 31, 2019 and 2018 were $22.9 and $22.7, respectively. Our wholly owned subsidiary, Enterprises, through subsidiaries, conducts (1) an LPG distribution business throughout much of Europe and (2) an energy marketing business in France, Belgium, the Netherlands and the United Kingdom. These businesses are conducted principally through our subsidiaries, UGI France, Flaga, AvantiGas, DVEP and UniverGas. Energy Services conducts directly and through subsidiaries energy marketing, midstream transmission, LNG, storage, natural gas gathering, natural gas production, electricity generation and energy services businesses primarily in the Mid-Atlantic region of the U.S. UGID owns all or a portion of electricity generation facilities principally located in Pennsylvania. HVAC, a first-tier subsidiary of Enterprises, also conducts heating, ventilation, air-conditioning, refrigeration and electrical contracting businesses in portions of eastern and central Pennsylvania. Energy Services and its subsidiaries’ storage, LNG and portions of its midstream transmission operations are subject to regulation by the FERC. UGI Utilities owns and operates Gas Utility, a natural gas distribution utility business in eastern and central Pennsylvania and in a portion of one Maryland county directly and, prior to the Utility Merger on October 1, 2018, through PNG and CPG. Gas Utility is subject to regulation by the PAPUC and the FERC and, with respect to a small service territory in one Maryland county, the MDPSC. UGI Utilities also owns and operates Electric Utility, an electric distribution utility located in northeastern Pennsylvania. Electric Utility is subject to regulation by the PAPUC and the FERC. Proposed Merger On April 1, 2019, we entered into the Merger Agreement, pursuant to which Merger Sub will merge with and into the Partnership, with the Partnership surviving as an indirect, wholly owned subsidiary of UGI. Under the terms of the Merger Agreement, at the effective time of the Proposed Merger, each outstanding Common Unit other than Common Units owned by UGI and its subsidiaries, including the General Partner, will be converted into the right to receive, at the election of each holder of such Common Units, one of the following forms of merger consideration: (i)0.6378 shares of UGI common stock (such election, a "Share Election," such ratio of shares of UGI common stock received per Common Unit, the "Share Election Exchange Ratio"); (ii)$7.63 in cash, without interest, and 0.500 shares of UGI common stock (such election, a "Mixed Election," such ratio of shares of UGI common stock received per Common Unit, the "Mixed Election Exchange Ratio"); or (iii)$35.325 in cash, without interest (such election, a "Cash Election"). The merger consideration is subject to proration designed to ensure that the total number of shares of UGI common stock issuable as merger consideration will equal approximately 34.6 million shares, and the amount of cash consideration paid will equal approximately $530. Also, at the effective time of the Proposed Merger, the General Partner’s 1% economic general partner interest in AmeriGas Partners, which includes its incentive distribution rights, will convert into (i) 10,615,711 Common Units, which will remain outstanding as partnership interests in AmeriGas Partners, and (ii) a non-economic general partner interest in AmeriGas Partners. Upon completion of the Proposed Merger, Common Units will no longer be publicly traded. Subject to the satisfaction or waiver of certain conditions, including the approval of the Merger Agreement by the Partnership’s unitholders, the Proposed Merger is expected to close in the fourth quarter of Fiscal 2019. The Proposed Merger will be accounted for in accordance with ASC 810, Consolidation - Overall-Changes in a Parent’s Ownership Interest in a Subsidiary. Because UGI controls the Partnership before and after the Proposed Merger, the changes in UGI’s ownership interest in the Partnership resulting from the merger will be accounted for as an equity transaction and no gain or loss will be recognized in UGI’s consolidated income statement resulting from the merger. In addition, the carrying amounts of AmeriGas’ assets and liabilities will not be adjusted. Finally, the tax effects of the merger will be reported as adjustments to deferred income taxes and UGI stockholders’ equity. See Note 17 for further information on the Proposed Merger.

Note 1 — Nature of Operations

UGI is a holding company that, through subsidiaries and affiliates, distributes, stores, transports and markets energy products and related services. In the United States, we (1) are the general partner and own limited partner interests in a retail propane marketing and distribution business; (2) own and operate natural gas and electric distribution utilities; and (3) own and operate an energy marketing, midstream infrastructure, storage, natural gas gathering, natural gas production, electricity generation and energy services business. In Europe, we market and distribute propane and other LPG and market energy products and services.

We conduct a domestic propane marketing and distribution business through AmeriGas Partners. AmeriGas Partners is a publicly traded limited partnership that conducts a national propane distribution business through its principal operating subsidiary, AmeriGas OLP. AmeriGas Partners and AmeriGas OLP are Delaware limited partnerships. UGI’s wholly owned second-tier subsidiary, AmeriGas Propane, Inc., serves as the General Partner of AmeriGas Partners and AmeriGas OLP. At March 31, 2019, the General Partner held a 1% general partner interest and a 25.3% limited partner interest in AmeriGas Partners and held an effective 27.0% ownership interest in AmeriGas OLP. Our limited partnership interest in AmeriGas Partners comprises Common Units. The remaining 73.7% interest in AmeriGas Partners comprises Common Units held by the public. The General Partner also holds incentive distribution rights that entitle it to receive distributions from AmeriGas Partners in excess of its 1% general partner interest under certain circumstances as further described in Note 14 of the Company’s 2018 Annual Report. Incentive distributions received by the General Partner during the six months ended March 31, 2019 and 2018 were $22.9 and $22.7, respectively.

Our wholly owned subsidiary, Enterprises, through subsidiaries, conducts (1) an LPG distribution business throughout much of Europe and (2) an energy marketing business in France, Belgium, the Netherlands and the United Kingdom. These businesses are conducted principally through our subsidiaries, UGI France, Flaga, AvantiGas, DVEP and UniverGas.

Energy Services conducts directly and through subsidiaries energy marketing, midstream transmission, LNG, storage, natural gas gathering, natural gas production, electricity generation and energy services businesses primarily in the Mid-Atlantic region of the U.S. UGID owns all or a portion of electricity generation facilities principally located in Pennsylvania. HVAC, a first-tier subsidiary of Enterprises, also conducts heating, ventilation, air-conditioning, refrigeration and electrical contracting businesses in portions of eastern and central Pennsylvania. Energy Services and its subsidiaries’ storage, LNG and portions of its midstream transmission operations are subject to regulation by the FERC.

UGI Utilities owns and operates Gas Utility, a natural gas distribution utility business in eastern and central Pennsylvania and in a portion of one Maryland county directly and, prior to the Utility Merger on October 1, 2018, through PNG and CPG. Gas Utility is subject to regulation by the PAPUC and the FERC and, with respect to a small service territory in one Maryland county, the MDPSC. UGI Utilities also owns and operates Electric Utility, an electric distribution utility located in northeastern Pennsylvania. Electric Utility is subject to regulation by the PAPUC and the FERC.

Proposed Merger

On April 1, 2019, we entered into the Merger Agreement, pursuant to which Merger Sub will merge with and into the Partnership, with the Partnership surviving as an indirect, wholly owned subsidiary of UGI. Under the terms of the Merger Agreement, at the effective time of the Proposed Merger, each outstanding Common Unit other than Common Units owned by UGI and its subsidiaries, including the General Partner, will be converted into the right to receive, at the election of each holder of such Common Units, one of the following forms of merger consideration:

(i)0.6378 shares of UGI common stock (such election, a "Share Election," such ratio of shares of UGI common stock received per Common Unit, the "Share Election Exchange Ratio");

(ii)$7.63 in cash, without interest, and 0.500 shares of UGI common stock (such election, a "Mixed Election," such ratio of shares of UGI common stock received per Common Unit, the "Mixed Election Exchange Ratio"); or

(iii)$35.325 in cash, without interest (such election, a "Cash Election").

The merger consideration is subject to proration designed to ensure that the total number of shares of UGI common stock issuable as merger consideration will equal approximately 34.6 million shares, and the amount of cash consideration paid will equal approximately $530. Also, at the effective time of the Proposed Merger, the General Partner’s 1% economic general partner interest in AmeriGas Partners, which includes its incentive distribution rights, will convert into (i) 10,615,711 Common Units, which will remain outstanding as partnership interests in AmeriGas Partners, and (ii) a non-economic general partner interest in AmeriGas Partners.

Upon completion of the Proposed Merger, Common Units will no longer be publicly traded. Subject to the satisfaction or waiver of certain conditions, including the approval of the Merger Agreement by the Partnership’s unitholders, the Proposed Merger is expected to close in the fourth quarter of Fiscal 2019.

The Proposed Merger will be accounted for in accordance with ASC 810, Consolidation - Overall-Changes in a Parent’s Ownership Interest in a Subsidiary. Because UGI controls the Partnership before and after the Proposed Merger, the changes in UGI’s ownership interest in the Partnership resulting from the merger will be accounted for as an equity transaction and no gain or loss will be recognized in UGI’s consolidated income statement resulting from the merger. In addition, the carrying amounts of AmeriGas’ assets and liabilities will not be adjusted. Finally, the tax effects of the merger will be reported as adjustments to deferred income taxes and UGI stockholders’ equity.

See Note 17 for further information on the Proposed Merger.