Employee Retirement Plans (Fair values of pension plans' assets and VEBA trust assets) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Pension Benefits [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	$ 398,171	$ 351,543	$ 289,764
Pension Benefits [Member] | S&P 500 Index equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	141,774	118,922
Pension Benefits [Member] | Small and Midcap equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	54,528	42,876
Pension Benefits [Member] | UGI Corporation Common Stock [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	32,551	26,445
Pension Benefits [Member] | Domestic [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	228,853	188,243
Pension Benefits [Member] | International [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	44,452	36,908
Pension Benefits [Member] | Bond index mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	120,906	123,332
Pension Benefits [Member] | Cash equivalents [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	3,960	3,060
Pension Benefits [Member] | Fixed income [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	124,866	126,392
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	394,211	348,483
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | S&P 500 Index equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	141,774	118,922
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Small and Midcap equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	54,528	42,876
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | UGI Corporation Common Stock [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	32,551	26,445
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Domestic [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	228,853	188,243
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	44,452	36,908
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Bond index mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	120,906	123,332
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Cash equivalents [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Fixed income [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	120,906	123,332
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	3,960	3,060
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | S&P 500 Index equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Small and Midcap equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | UGI Corporation Common Stock [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Domestic [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Bond index mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Cash equivalents [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	3,960	3,060
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Fixed income [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	3,960	3,060
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | S&P 500 Index equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Small and Midcap equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | UGI Corporation Common Stock [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Domestic [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Bond index mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Cash equivalents [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Fixed income [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
VEBA Trust [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	11,723	11,205
VEBA Trust [Member] | S&P 500 Index equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	7,693	7,678
VEBA Trust [Member] | Bond index mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	3,794	3,366
VEBA Trust [Member] | Cash equivalents [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	236	161
VEBA Trust [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	11,487	11,044
VEBA Trust [Member] | Fair Value, Inputs, Level 1 [Member] | S&P 500 Index equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	7,693	7,678
VEBA Trust [Member] | Fair Value, Inputs, Level 1 [Member] | Bond index mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	3,794	3,366
VEBA Trust [Member] | Fair Value, Inputs, Level 1 [Member] | Cash equivalents [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
VEBA Trust [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	236	161
VEBA Trust [Member] | Fair Value, Inputs, Level 2 [Member] | S&P 500 Index equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
VEBA Trust [Member] | Fair Value, Inputs, Level 2 [Member] | Bond index mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
VEBA Trust [Member] | Fair Value, Inputs, Level 2 [Member] | Cash equivalents [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	236	161
VEBA Trust [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
VEBA Trust [Member] | Fair Value, Inputs, Level 3 [Member] | S&P 500 Index equity mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
VEBA Trust [Member] | Fair Value, Inputs, Level 3 [Member] | Bond index mutual funds [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	0	0
VEBA Trust [Member] | Fair Value, Inputs, Level 3 [Member] | Cash equivalents [Member]
Fair Value of Pension Plan Assets
Fair Value of Plan Assets	$ 0	$ 0