SCHEDULE I — CONDENSED FINANCIAL INFORMATION OF REGISTRANT (PARENT COMPANY) - STATEMENTS OF INCOME (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Condensed Financial Statements, Captions
Revenues	$ 1,150.4	$ 1,363.7	$ 2,606.1	$ 2,200.2	$ 1,273.1	$ 1,440.9	$ 2,812.0	$ 2,125.2	$ 7,320.4	$ 7,651.2	$ 6,120.7
Costs and expenses:
Operating and administrative expenses									1,963.2	2,012.8	1,867.6
Other operating income, net									(31.1)	(31.3)	(10.5)
Total costs and expenses									6,703.3	6,586.5	5,110.7
Operating income	(99.0)	9.6	538.8	167.7	49.2	29.5	591.0	395.0	617.1	1,064.7	1,010.0
Pension and other postretirement plans non-service expense									0.5	(0.6)	(5.8)
Interest expense									(257.8)	(230.1)	(223.5)
Income tax (benefit) expense									92.6	32.1	177.6
Equity in income of unconsolidated subsidiaries									9.1	4.3	4.3
Net income attributable to UGI Corporation	$ (51.5)	$ (1.9)	$ 245.4	$ 64.2	$ 24.4	$ 52.4	$ 276.0	$ 365.9	256.2	718.7	436.6
Comprehensive income attributable to UGI Corporation									$ 156.6	$ 701.7	$ 497.9
Earnings per common share attributable to UGI Corporation stockholders:
Basic (in dollars per share)	$ (0.27)	$ (0.01)	$ 1.41	$ 0.37	$ 0.14	$ 0.30	$ 1.59	$ 2.11	$ 1.44	$ 4.13	$ 2.51
Diluted (in dollars per share)	$ (0.27)	$ (0.01)	$ 1.38	$ 0.36	$ 0.14	$ 0.30	$ 1.57	$ 2.07	$ 1.41	$ 4.06	$ 2.46
Weighted - average common shares outstanding (thousands):
Basic (in shares)	189,905	174,759	174,501	174,413	174,391	173,991	173,570	173,670	178,417	173,908	173,662
Diluted (in shares)	189,905	174,759	177,318	177,566	177,506	176,807	176,350	176,948	181,111	176,905	177,159
Parent Company
Condensed Financial Statements, Captions
Revenues									$ 0.0	$ 0.0	$ 0.0
Costs and expenses:
Operating and administrative expenses									50.0	63.4	44.5
Other operating income, net									(49.7)	(52.2)	(45.9)
Total costs and expenses									0.3	11.2	(1.4)
Operating income									(0.3)	(11.2)	1.4
Pension and other postretirement plans non-service expense									(0.9)	(1.3)	(1.8)
Interest expense									(6.4)
Intercompany interest income									0.3	0.1	0.0
Loss before income taxes									(7.3)	(12.4)	(0.4)
Income tax (benefit) expense									(2.8)	6.1	(5.7)
(Loss) income before equity in income of unconsolidated subsidiaries									(4.5)	(18.5)	5.3
Equity in income of unconsolidated subsidiaries									260.7	737.2	431.3
Net income attributable to UGI Corporation									256.2	718.7	436.6
Other comprehensive (loss) income									(3.3)	3.4	1.3
Equity in other comprehensive (loss) income of unconsolidated subsidiaries									(96.3)	(20.4)	60.0
Comprehensive income attributable to UGI Corporation									$ 156.6	$ 701.7	$ 497.9
Earnings per common share attributable to UGI Corporation stockholders:
Basic (in dollars per share)									$ 1.44	$ 4.13	$ 2.51
Diluted (in dollars per share)									$ 1.41	$ 4.06	$ 2.46
Weighted - average common shares outstanding (thousands):
Basic (in shares)									178,417	173,908	173,662
Diluted (in shares)									181,111	176,905	177,159