Employee Retirement Plans (Details) - USD ($)	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plan Disclosure
Amortization of net actuarial losses	$ 11,000,000
Amortization of prior service credits	200,000
Projected benefit obligations of unfunded and non qualified supplemental executive retirement plans	40,100,000	$ 38,400,000
Net cost to sponsor unfunded and non-qualified supplemental executive retirement plans	2,300,000	2,600,000	$ 3,000,000
Amounts recorded in UGI's stockholders include pre-tax losses representing unrecognized actuarial losses	(10,100,000)	$ (10,200,000)
Amount of expected amortization of pre-tax actuarial losses into retiree benefit cost	$ 1,000,000
Percentage of aggregate employer securities holdings to not to exceed fair value assets	10.00%
Percentage of common stock represented pension plan assets	10.10%	9.60%
Costs of benefits under savings plans	$ 15,200,000	$ 14,700,000	14,000,000
Supplemental Employee Retirement Plans
Defined Benefit Plan Disclosure
Pension and Other Postretirement Benefit contributions	0	300,000	21,600,000
Portion Used to Fund Company Established Trusts | Supplemental Employee Retirement Plans
Defined Benefit Plan Disclosure
Pension and Other Postretirement Benefit contributions			21,000,000
Other Assets | Supplemental Defined Contribution Executive Retirement Plans
Defined Benefit Plan Disclosure
Fair value of Pension and Other Postretirement Benefit contributions	4,200,000	3,400,000
Other Assets | Supplemental Employee Retirement Plans
Defined Benefit Plan Disclosure
Fair value of Pension and Other Postretirement Benefit contributions	26,100,000	26,600,000
U.S Pension Plans
Defined Benefit Plan Disclosure
ABO for the Pension Plans	523,700,000	499,100,000
Contribution made to Pension Plan	11,100,000	19,200,000	$ 22,400,000
Fair value of Pension and Other Postretirement Benefit contributions	$ 430,800,000	$ 442,400,000