Employee Retirement Plans (Net periodic pension expense and other postretirement benefit costs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Pension Benefits [Member]
Components of Net periodic pension expense and other postretirement benefit costs [Abstract]
Service cost	$ 9,385	$ 8,063
Interest cost	22,784	24,095
Other Postretirement Benefits [Member]
Components of Net periodic pension expense and other postretirement benefit costs [Abstract]
Service cost	223	162
Interest cost	587	665
UGI Utilities Employees [Member] | Pension Benefits [Member]
Components of Net periodic pension expense and other postretirement benefit costs [Abstract]
Service cost	8,211	7,025	7,176
Interest cost	20,783	22,376	22,047
Expected return on assets	(24,791)	(23,762)	(23,937)
Curtailment gain	0	0	0
Amortization of:
Prior service cost (benefit)	249	249	302
Actuarial loss	13,463	7,853	6,838
Net benefit cost (income)	17,915	13,741	12,426
Change in associated regulatory liabilities	0	0	0
Benefit cost (income) after change in regulatory liabilities	17,915	13,741	12,426
UGI Utilities Employees [Member] | Other Postretirement Benefits [Member]
Components of Net periodic pension expense and other postretirement benefit costs [Abstract]
Service cost	205	152	202
Interest cost	557	639	678
Expected return on assets	(529)	(481)	(523)
Curtailment gain	0	0	(3,245)
Amortization of:
Prior service cost (benefit)	(420)	(422)	(694)
Actuarial loss	336	355	427
Net benefit cost (income)	149	243	(3,155)
Change in associated regulatory liabilities	3,302	3,188	3,138
Benefit cost (income) after change in regulatory liabilities	$ 3,451	$ 3,431	$ (17)