Discontinued Operations (Schedule of Operating Results) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016		Mar. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net Income Attributable to Noncontrolling Interests of Discontinued Operations	$ 0.0			$ 2.1
Net Income (Loss) From Discontinued Operations, net of tax	48.2			82.7
Discontinued Operations, Allowance Adjustment Effect on Income Tax Provision	66.0
Energy-from-Waste [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on Disposal, net of tax	47.1		$ 846.6
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales	254.8			489.5
Cost of sales	179.0			299.9
Selling and administrative	20.4			37.4
Research and development	5.1			15.1
Other income (expense), net	(6.9)			(16.6)
Operating Income (Loss)	43.4			120.5
Equity affiliates’ income	0.3			0.4
Income (Loss) Before Taxes	43.7			120.9	[1]
Income tax provision	(51.6)	[2]		36.1
Income (Loss) From Operations of Discontinued Operations, net of tax	95.3			84.8
Loss on Disposal, net of tax	(47.1)
Net Income Attributable to Noncontrolling Interests of Discontinued Operations				2.1
Net Income (Loss) From Discontinued Operations, net of tax	48.2			82.7
Income (Loss) from Discontinued Operations, Before Income Tax, Attributable to Parent				118.4
Discontinued Operations [Member] | Electronic Materials Division [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales				242.6
Cost of sales				127.3
Selling and administrative				18.4
Research and development				10.1
Other income (expense), net				2.2
Operating Income (Loss)				89.0
Equity affiliates’ income				0.2
Income (Loss) Before Taxes				89.2
Income tax provision				24.9
Income (Loss) From Operations of Discontinued Operations, net of tax				64.3
Net Income Attributable to Noncontrolling Interests of Discontinued Operations				2.1
Net Income (Loss) From Discontinued Operations, net of tax				62.2
Discontinued Operations [Member] | Performance Materials Division [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales	254.8			246.9
Cost of sales	179.0			172.6
Selling and administrative	20.4			19.0
Research and development	5.1			5.0
Other income (expense), net	(0.4)			(1.2)
Operating Income (Loss)	49.9			49.1
Equity affiliates’ income	0.3			0.2
Income (Loss) Before Taxes	50.2			49.3
Income tax provision	(50.5)	[2]		14.5
Income (Loss) From Operations of Discontinued Operations, net of tax	100.7			34.8
Loss on Disposal, net of tax	0.0
Net Income Attributable to Noncontrolling Interests of Discontinued Operations				0.0
Net Income (Loss) From Discontinued Operations, net of tax	100.7			34.8
Discontinued Operations [Member] | Energy-from-Waste [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales	0.0			0.0
Cost of sales	0.0			0.0
Selling and administrative	0.0			0.0
Research and development	0.0			0.0
Other income (expense), net	(6.5)	[3]		(17.6)	[4]
Operating Income (Loss)	(6.5)	[3]		(17.6)	[4]
Equity affiliates’ income	0.0			0.0
Income (Loss) Before Taxes	(6.5)	[3]		(17.6)	[4]
Income tax provision	(1.1)			(3.3)
Income (Loss) From Operations of Discontinued Operations, net of tax	(5.4)	[3]		(14.3)	[4]
Loss on Disposal, net of tax	(47.1)
Net Income Attributable to Noncontrolling Interests of Discontinued Operations				0.0
Net Income (Loss) From Discontinued Operations, net of tax	$ (52.5)			$ (14.3)	[4]

[1] For the three months ended 31 December 2015, income before taxes from operations of discontinued operations attributable to Air Products was $118.4.

[2] As a result of the expected gain on sale of PMD that closed in the second quarter of 2017, we released valuation allowances related to capital loss and net operating loss carryforwards that favorably impacted our income tax provision within discontinued operations by approximately $66 during the first quarter of 2017.

[3] The loss from operations of discontinued operations for EfW primarily relates to land leases, administrative costs, and costs incurred for ongoing project exit activities.

[4] The loss from operations of discontinued operations for EfW primarily relates to project suspension costs, land leases, and administrative costs.