Employee Retirement Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Amounts recorded in UGI Corporation stockholders' equity (pre-tax):
Net actuarial loss (gain)	$ 11.0	$ 7.6
Pension Benefit [Member]
Change in benefit obligations:
Benefit obligations - beginning of year	462.9	471.8
Service cost	9.3	8.8	8.7
Interest cost	25.1	24.1	23.5
Actuarial loss (gain)	82.4	(22.0)
Plan amendments	0.1
Acquisitions	14.6
Foreign currency	(0.7)	(0.1)
Benefits paid	(20.3)	(19.7)
Benefit obligations - end of year	573.4	462.9	471.8
Change in plan assets:
Fair value of plan assets - beginning of year	290.0	287.9
Actual gain on plan assets	51.2	2.6
Foreign currency	(0.5)
Employer contributions	32.2	19.2
Acquisitions	17.3
Benefits paid	(20.3)	(19.7)
Fair value of plan assets - end of year	369.9	290.0	287.9
Funded status of the plans - end of year	(203.5)	(172.9)
(Liabilities) recorded in the balance sheet:
Unfunded liabilities - included in other current liabilities	(15.8)	(27.6)
Unfunded liabilities - included in other noncurrent liabilities	(187.7)	(145.3)
Net amount recognized	(203.5)	(172.9)
Amounts recorded in UGI Corporation stockholders' equity (pre-tax):
Prior service credit	(0.1)	(0.2)
Net actuarial loss (gain)	25.3	13.6
Total	25.2	13.4
Amounts recorded in regulatory assets and liabilities (pre-tax):
Prior service cost (credit)	1.5	1.8
Net actuarial loss	184.5	146.9
Total	186.0	148.7
Other Postretirement Benefits [Member]
Change in benefit obligations:
Benefit obligations - beginning of year	20.5	22.9
Service cost	0.4	0.4	0.4
Interest cost	1.1	1.1	1.1
Actuarial loss (gain)	3.2	(2.4)
Plan amendments	1.0	(0.1)
Acquisitions
Foreign currency	(0.1)
Benefits paid	(1.4)	(1.4)
Benefit obligations - end of year	24.7	20.5	22.9
Change in plan assets:
Fair value of plan assets - beginning of year	9.8	10.0
Actual gain on plan assets	1.7	0.1
Foreign currency
Employer contributions	1.1	1.1
Acquisitions
Benefits paid	(1.4)	(1.4)
Fair value of plan assets - end of year	11.2	9.8	10.0
Funded status of the plans - end of year	(13.5)	(10.7)
(Liabilities) recorded in the balance sheet:
Unfunded liabilities - included in other current liabilities	(0.6)	(0.6)
Unfunded liabilities - included in other noncurrent liabilities	(12.9)	(10.1)
Net amount recognized	(13.5)	(10.7)
Amounts recorded in UGI Corporation stockholders' equity (pre-tax):
Prior service credit	(0.1)	(0.1)
Net actuarial loss (gain)	0.4	(0.8)
Total	0.3	(0.9)
Amounts recorded in regulatory assets and liabilities (pre-tax):
Prior service cost (credit)	(2.8)	(3.2)
Net actuarial loss	5.8	6.3
Total	$ 3.0	$ 3.1