Cost Reduction and Asset Actions (Narrative) (Details) $ / shares in Units, $ in Millions		3 Months Ended		12 Months Ended
		Dec. 31, 2016 USD ($) position $ / shares	Dec. 31, 2015 USD ($)	Sep. 30, 2016 USD ($) position
Restructuring and Related Cost [Abstract]
Cost reduction and asset actions		$ 50.0	$ 0.0
Asset Actions [Member] | Industrial Gases - EMEA [Member]
Restructuring and Related Cost [Abstract]
Cost reduction and asset actions	[1]	45.7
Cost Reduction Actions [Member]
Restructuring and Related Cost [Abstract]
Net cost reduction and asset actions		50.0
Net cost reduction and asset actions, after-tax		$ 41.2
Net cost reduction and asset actions, per share | $ / shares		$ 0.19
Cost reduction and asset actions		$ 53.4		$ 34.5
Favorable restructuring reserve settlement		$ 3.4
Number of positions eliminated | position		50		610
Cost Reduction Actions [Member] | Asset Actions [Member]
Restructuring and Related Cost [Abstract]
Cost reduction and asset actions		$ 45.7		$ 0.0
Cost Reduction Actions [Member] | Severance And Other Benefits [Member]
Restructuring and Related Cost [Abstract]
Cost reduction and asset actions		$ 7.7		$ 34.5

[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. For additional information, see Note 3, Discontinued Operations and Note 5, Cost Reduction and Asset Actions.