Fair Value Measurements (Schedule Of Fair Value Of Assets And Liabilities) (Details) (USD $) In Millions	Sep. 30, 2011	Sep. 30, 2010
Other investments		$ 1.1
Total Assets at Fair Value	118.2	218.0
Other liabilities	51.0	42.0
Total Liabilities at Fair Value	94.8	96.2
Interest Rate Swap Contracts [Member]
Derivative assets	48.2	39.7
Derivative liabilities	6.0	3.7
Interest Rate Swap Contracts [Member] | Fair Value [Member]
Derivative assets	48.2	39.7
Derivative liabilities	6.0	3.7
Interest Rate Swap Contracts [Member] | Level 1 [Member]
Derivative assets
Derivative liabilities
Interest Rate Swap Contracts [Member] | Level 2 [Member]
Derivative assets	48.2	39.7
Derivative liabilities	6.0	3.7
Interest Rate Swap Contracts [Member] | Level 3 [Member]
Derivative assets
Derivative liabilities
Foreign Exchange Forward [Member]
Derivative assets	70.0	74.7
Derivative liabilities	37.8	50.5
Foreign Exchange Forward [Member] | Fair Value [Member]
Derivative assets	70.0	74.7
Derivative liabilities	37.8	50.5
Foreign Exchange Forward [Member] | Level 1 [Member]
Derivative assets
Derivative liabilities
Foreign Exchange Forward [Member] | Level 2 [Member]
Derivative assets	70.0	74.7
Derivative liabilities	37.8	50.5
Foreign Exchange Forward [Member] | Level 3 [Member]
Derivative assets
Derivative liabilities
Airgas [Member] | Fair Value [Member]
Available-for-sale securities		102.5
Fair Value [Member]
Other investments		1.1
Other liabilities	51.0	42.0
Airgas [Member] | Level 1 [Member]
Available-for-sale securities		102.5
Level 1 [Member]
Other investments		1.1
Total Assets at Fair Value		103.6
Other liabilities
Total Liabilities at Fair Value
Airgas [Member] | Level 2 [Member]
Available-for-sale securities
Level 2 [Member]
Other investments
Total Assets at Fair Value	118.2	114.4
Other liabilities
Total Liabilities at Fair Value	43.8	54.2
Airgas [Member] | Level 3 [Member]
Available-for-sale securities
Level 3 [Member]
Other investments
Total Assets at Fair Value
Other liabilities	51.0	42.0
Total Liabilities at Fair Value	51.0	42.0
Airgas [Member]
Available-for-sale securities		$ 102.5