Equity (Changes In Equity) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Schedule of Capitalization, Equity [Line Items]
Balance, beginning of period	$ 6,057.1	$ 5,977.2	$ 5,938.7	$ 5,697.6
Net Income	302.2	311.5	558.5	587.4
Translation adjustments	133.9	116.4	95.7	164.4
Net gain (loss) on derivatives	(1.1)	8.6	(10.4)	2.4
Unrealized holding gain (loss) on available-for-sale securities		0.6		(4.6)
Derivatives	2.1	(1.6)	12.0	5.4
Available-for-sale securities		(15.9)		(16.1)
Pension and postretirement benefits	16.0	17.1	32.1	33.6
Total Other Comprehensive Income	150.9	125.2	129.4	185.1
Comprehensive Income	453.1	436.7	687.9	772.5
Dividends on common stock	(135.3)	(122.9)	(257.5)	(228.2)
Dividends to noncontrolling interests	(13.0)	(0.5)	(13.0)	(0.5)
Share-based compensation expense	15.2	11.7	27.0	21.9
Purchase of treasury shares	(53.1)	(350.0)	(53.1)	(350.0)
Issuance of treasury shares for stock option and award plans	64.1	33.4	61.8	65.0
Tax benefit of stock option and award plans	21.2	14.5	25.4	27.8
Purchase of noncontrolling interests			(6.3)	(6.1)
Contribution from noncontrolling interests				1.4
Other equity transactions	(1.9)	(0.9)	(3.5)	(2.2)
Balance, end of period	6,407.4	5,999.2	6,407.4	5,999.2
Dividends per share	$ 0.64	$ 0.58	$ 1.22	$ 1.07
Air Products [Member]
Schedule of Capitalization, Equity [Line Items]
Balance, beginning of period	5,909.0	5,810.0	5,795.8	5,546.9
Net Income	296.0	304.3	544.1	572.9
Translation adjustments	130.4	116.3	91.4	156.4
Net gain (loss) on derivatives	(1.0)	8.6	(10.2)	2.5
Unrealized holding gain (loss) on available-for-sale securities		0.6		(4.6)
Derivatives	2.1	(1.6)	12.0	5.4
Available-for-sale securities		(15.9)		(16.1)
Pension and postretirement benefits	16.0	17.1	32.1	33.6
Total Other Comprehensive Income	147.5	125.1	125.3	177.2
Comprehensive Income	443.5	429.4	669.4	750.1
Dividends on common stock	(135.3)	(122.9)	(257.5)	(228.2)
Share-based compensation expense	15.2	11.7	27.0	21.9
Purchase of treasury shares	(53.1)	(350.0)	(53.1)	(350.0)
Issuance of treasury shares for stock option and award plans	64.1	33.4	61.8	65.0
Tax benefit of stock option and award plans	21.2	14.5	25.4	27.8
Purchase of noncontrolling interests			(4.4)	(6.1)
Other equity transactions	(1.9)	(0.9)	(1.7)	(2.2)
Balance, end of period	6,262.7	5,825.2	6,262.7	5,825.2
Non-Controlling Interests [Member]
Schedule of Capitalization, Equity [Line Items]
Balance, beginning of period	148.1	167.2	142.9	150.7
Net Income	6.2	7.2	14.4	14.5
Translation adjustments	3.5	0.1	4.3	8.0
Net gain (loss) on derivatives	(0.1)		(0.2)	(0.1)
Total Other Comprehensive Income	3.4	0.1	4.1	7.9
Comprehensive Income	9.6	7.3	18.5	22.4
Dividends to noncontrolling interests	(13.0)	(0.5)	(13.0)	(0.5)
Purchase of noncontrolling interests			(1.9)
Contribution from noncontrolling interests				1.4
Other equity transactions			(1.8)
Balance, end of period	$ 144.7	$ 174.0	$ 144.7	$ 174.0