Employee Retirement Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Amounts recorded in UGI Corporation stockholders' equity (pre-tax):
Net actuarial loss (gain)	$ 9.4	$ 11.0
Pension Benefit [Member]
Change in benefit obligations:
Benefit obligations - beginning of year	573.4	462.9
Service cost	11.3	9.3	8.8
Interest cost	23.8	25.1	24.1
Actuarial (gain) loss	(72.7)	82.4
Plan amendments	1.0	0.1
Acquisitions		14.6
Foreign currency	1.5	(0.7)
Benefits paid	(21.8)	(20.3)
Benefit obligations - end of year	516.5	573.4	462.9
Change in plan assets:
Fair value of plan assets - beginning of year	369.9	290.0
Actual gain on plan assets	42.2	51.2
Foreign currency	0.8	(0.5)
Employer contributions	24.2	32.2
Acquisitions		17.3
Benefits paid	(21.8)	(20.3)
Fair value of plan assets - end of year	415.3	369.9	290.0
Funded status of the plans - end of year	(101.2)	(203.5)
Assets (liabilities) recorded in the balance sheet:
Assets in excess of liabilities — included in other noncurrent assets	0	0
Unfunded liabilities - included in other current liabilities	(17.9)	(15.8)
Unfunded liabilities - included in other noncurrent liabilities	(83.3)	(187.7)
Net amount recognized	(101.2)	(203.5)
Amounts recorded in UGI Corporation stockholders' equity (pre-tax):
Prior service credit	(0.1)	(0.1)
Net actuarial loss (gain)	16.7	25.3
Total	16.6	25.2
Amounts recorded in regulatory assets and liabilities (pre-tax):
Prior service cost (credit)	2.2	1.5
Net actuarial loss	91.3	184.5
Total	93.5	186.0
Other Postretirement Benefits [Member]
Change in benefit obligations:
Benefit obligations - beginning of year	24.7	20.5
Service cost	0.6	0.4	0.4
Interest cost	0.9	1.1	1.1
Actuarial (gain) loss	(3.6)	3.2
Plan amendments	(1.8)	1.0
Acquisitions
Foreign currency	0.2	(0.1)
Benefits paid	(1.3)	(1.4)
Benefit obligations - end of year	19.7	24.7	20.5
Change in plan assets:
Fair value of plan assets - beginning of year	11.2	9.8
Actual gain on plan assets	1.1	1.7
Foreign currency
Employer contributions	0.7	1.1
Acquisitions
Benefits paid	(1.3)	(1.4)
Fair value of plan assets - end of year	11.7	11.2	9.8
Funded status of the plans - end of year	(8.0)	(13.5)
Assets (liabilities) recorded in the balance sheet:
Assets in excess of liabilities — included in other noncurrent assets	3.2	0
Unfunded liabilities - included in other current liabilities	(0.4)	(0.6)
Unfunded liabilities - included in other noncurrent liabilities	(10.8)	(12.9)
Net amount recognized	(8.0)	(13.5)
Amounts recorded in UGI Corporation stockholders' equity (pre-tax):
Prior service credit	(0.1)	(0.1)
Net actuarial loss (gain)	(0.4)	0.4
Total	(0.5)	0.3
Amounts recorded in regulatory assets and liabilities (pre-tax):
Prior service cost (credit)	(4.3)	(2.8)
Net actuarial loss	3.6	5.8
Total	$ (0.7)	$ 3.0