Fair Value Measurements (Schedule of Nonrecurring Fair Value Measurements) (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Long Lived Assets Held-for-sale [Line Items]
Property and equipment, total loss		$ 10.3		$ 10.7	$ 60.3	$ 10.7
Industrial Gases - EMEA [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Property and equipment, total loss			$ 45.7
Continuing Operations [Member] | Industrial Gases - EMEA [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Property and equipment, total loss					45.7
Discontinued Operations [Member] | Energy From Waste [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, total loss	[1]				$ 6.3
Nonrecurring Basis [Member] | Continuing Operations [Member] | Industrial Gases - EMEA [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Property and equipment, fair value	[1]		1.4
Nonrecurring Basis [Member] | Discontinued Operations [Member] | Energy From Waste [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, fair value	[1]		11.0
Nonrecurring Basis [Member] | Level 1 [Member] | Continuing Operations [Member] | Industrial Gases - EMEA [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Property and equipment, fair value	[1]		0.0
Nonrecurring Basis [Member] | Level 1 [Member] | Discontinued Operations [Member] | Energy From Waste [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, fair value	[1]		0.0
Nonrecurring Basis [Member] | Level 2 [Member] | Continuing Operations [Member] | Industrial Gases - EMEA [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Property and equipment, fair value	[1]		0.0
Nonrecurring Basis [Member] | Level 2 [Member] | Discontinued Operations [Member] | Energy From Waste [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, fair value	[1]		0.0
Nonrecurring Basis [Member] | Level 3 [Member] | Continuing Operations [Member] | Industrial Gases - EMEA [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Property and equipment, fair value	[1]		1.4
Nonrecurring Basis [Member] | Level 3 [Member] | Discontinued Operations [Member] | Energy From Waste [Member] | Asset Actions [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, fair value	[1]		$ 11.0

[1] We assessed the recoverability of the carrying value of assets associated with the EfW discontinued operation, including the air separation unit within continuing operations of our Industrial Gases – EMEA segment. We based our estimates primarily on an orderly liquidation valuation which resulted in losses for the difference between the orderly liquidation value and net book value of the assets as of 31 December 2016. There have been no significant updates to our estimates as of 31 March 2017. For additional information, see Note 3, Discontinued Operations and Note 5, Cost Reduction and Asset Actions.