Common Stock and Equity-Based Compensation - Common Stock Share Activity (Details) - UGI Corporation Common Stock - shares	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Common Stock Share Activity
Beginning balance - shares issued (in shares)	173,894,141	173,806,991	173,770,641
Beginning balance - shares outstanding (in shares)	172,960,449	172,388,503	172,273,781
Employee and director plans - shares issued (in shares)	93,550	87,150	36,350
Employee and director plans - shares outstanding (in shares)	1,145,254	2,442,352	1,191,726
Sal of reacquired common stock - shares outstanding (in shares)	50,000
Repurchases of common stock - shares outstanding (in shares)	(900,000)	(1,250,000)	(1,000,000)
Reacquired common stock, employee and director plans - shares outstanding (in shares)	(111,966)	(620,406)	(77,004)
Ending balance - shares issued (in shares)	173,987,691	173,894,141	173,806,991
Ending balance - shares outstanding (in shares)	173,143,737	172,960,449	172,388,503
Treasury
Common Stock Share Activity
Beginning balance - shares issued (in shares)	(933,692)	(1,418,488)	(1,496,860)
Employee and director plans - shares issued (in shares)	1,051,704	2,355,202	1,155,376
Sale of reacquired common stock - shares held in treasury (in shares)	50,000
Repurchases of common stock - held in treasury (in shares)	(900,000)	(1,250,000)	(1,000,000)
Reacquired common stock, employee and director plans - held in treasury (in shares)	(111,966)	(620,406)	(77,004)
Ending balance - shares issued (in shares)	(843,954)	(933,692)	(1,418,488)