Segment and Geographic Information Segment and Geographic Information (Details) - USD ($) $ in Millions	3 Months Ended											12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	[1]	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	[3]	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Segment Reporting Information [Line Items]
Sales to external customers												$ 988.8		$ 859.2		$ 1,040.2
Depreciation and amortization expense												41.9		37.5		45.4
Operating Income (Loss)	$ 21.3	[1],[2]	$ 10.5		$ 9.9	$ 0.3	$ 2.3	$ 20.1		$ 34.9	$ 0.1	42.0	[1],[2],[4],[5]	57.4	[5],[6]	(183.2)	[5],[7]
Total assets	1,724.7						1,233.0					1,724.7		1,233.0		1,200.1
Capital expenditures												35.2		17.8		47.1
Restructuring Costs												15.6		10.9		12.2
Acquisition-related expenses												10.1
Asset Impairments Charges and Other PP&E Impairment												0.0		1.2		255.1
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure												98.9
Segments, Geographical Areas [Abstract]
Property, plant and equipment, net	297.6						251.0					297.6		251.0
United States [Member]
Segment Reporting Information [Line Items]
Sales to external customers												526.7		426.0		513.7
Segments, Geographical Areas [Abstract]
Property, plant and equipment, net	177.9						145.0					177.9		145.0
China [Member]
Segment Reporting Information [Line Items]
Sales to external customers												110.0		147.7		110.0
Segments, Geographical Areas [Abstract]
Property, plant and equipment, net	82.9						75.4					82.9		75.4
Czech Republic [Member]
Segments, Geographical Areas [Abstract]
Property, plant and equipment, net	20.7						18.5					20.7		18.5
Germany [Member]
Segments, Geographical Areas [Abstract]
Property, plant and equipment, net	13.4						11.5					13.4		11.5
Other Non-U.S. Countries [Member]
Segment Reporting Information [Line Items]
Sales to external customers												352.1		285.5		416.5
Segments, Geographical Areas [Abstract]
Property, plant and equipment, net	2.7						0.6					2.7		0.6
Non-U.S. Countries [Member]
Segment Reporting Information [Line Items]
Sales to external customers												462.1		433.2		526.5
Segments, Geographical Areas [Abstract]
Property, plant and equipment, net	119.7						106.0					119.7		106.0
Energy & Chemicals [Member]
Segment Reporting Information [Line Items]
Sales to external customers												225.6		154.3		331.0
Depreciation and amortization expense												15.3		10.0		11.8
Operating Income (Loss)												5.1		13.3		(10.0)
Total assets	782.9						177.5					782.9		177.5		251.8
Capital expenditures												15.5		3.3		4.1
Restructuring Costs												2.4		1.0		1.4
Asset Impairments Charges and Other PP&E Impairment																68.8
Energy & Chemicals [Member] | Natural gas processing (including petrochemical) applications [Member]
Segment Reporting Information [Line Items]
Sales to external customers												152.9		105.4		180.9
Energy & Chemicals [Member] | Liquefied natural gas applications [Member]
Segment Reporting Information [Line Items]
Sales to external customers												29.5		38.2		136.1
Energy & Chemicals [Member] | Industrial gas applications [Member]
Segment Reporting Information [Line Items]
Sales to external customers												22.4		10.7		14.0
Energy & Chemicals [Member] | HVAC, power and refining [Member]
Segment Reporting Information [Line Items]
Sales to external customers												20.8		0.0		0.0
Distribution & Storage [Member]
Segment Reporting Information [Line Items]
Sales to external customers												540.3		497.1		487.6
Depreciation and amortization expense												18.8		18.4		18.3
Operating Income (Loss)												66.1		50.4		39.5
Total assets	685.2						657.6					685.2		657.6		689.1
Capital expenditures												14.4		11.7		36.8
Restructuring Costs												2.2		3.8		7.7
Asset Impairments Charges and Other PP&E Impairment												1.2		1.2		2.0
Distribution & Storage [Member] | Liquefied natural gas applications [Member]
Segment Reporting Information [Line Items]
Sales to external customers												137.7		109.8		115.9
Distribution & Storage [Member] | Bulk industrial gas applications [Member]
Segment Reporting Information [Line Items]
Sales to external customers												221.9		227.6		203.9
Distribution & Storage [Member] | Packaged gas industrial applications [Member]
Segment Reporting Information [Line Items]
Sales to external customers												180.7		159.7		167.8
BioMedical [Member]
Segment Reporting Information [Line Items]
Sales to external customers												222.9		207.8		221.6
Depreciation and amortization expense												5.6		6.0		12.0
Operating Income (Loss)												35.5		42.0		(165.3)
Total assets	165.9						178.7					165.9		178.7		224.4
Capital expenditures												3.0		2.3		3.9
Restructuring Costs												5.0		1.9		1.8
Asset Impairments Charges and Other PP&E Impairment																184.3
BioMedical [Member] | Respiratory therapy [Member]
Segment Reporting Information [Line Items]
Sales to external customers												124.4		118.9		132.3
BioMedical [Member] | Cryobiological storage [Member]
Segment Reporting Information [Line Items]
Sales to external customers												77.0		70.6		64.6
BioMedical [Member] | On-site generation systems [Member]
Segment Reporting Information [Line Items]
Sales to external customers												21.5		18.3		24.7
Corporate [Member]
Segment Reporting Information [Line Items]
Sales to external customers												0.0		0.0		0.0
Depreciation and amortization expense												2.2		3.1		3.3
Operating Income (Loss)												(64.7)		(48.3)		(47.4)
Total assets	$ 90.7						$ 219.2					90.7		219.2		34.8
Capital expenditures												2.3		0.5		2.3
Restructuring Costs												$ 6.0		4.2		$ 1.3
Cost of Sales [Member] | BioMedical [Member]
Segment Reporting Information [Line Items]
Product Warranty Expense														15.2
Selling, General and Administrative Expenses [Member] | BioMedical [Member]
Segment Reporting Information [Line Items]
Gain (Loss) Related to Litigation Settlement														$ 0.3

[1] Hudson, included in these results since the acquisition date, September 20, 2017, added net sales and operating income of $58.0 and $6.4 for the year ended December 31, 2017, including $6.1 and $1.2 in the third quarter and $51.9 and $5.2 in the fourth quarter, respectively.

[2] The fourth quarter of 2017 includes additional expense as a result of a litigation award in China. Refer to Note 18, Commitments and Contingencies, for further information.

[3] During the third quarter of 2016, we recovered for breaches of representations and warranties primarily related to warranty costs for certain product lines acquired in the 2012 acquisition of AirSep under the related representation and warranty insurance. For the year ended December 31, 2016, this reduced BioMedical segment’s cost of sales by $15.2 and Corporate SG&A expenses by $0.3, net of associated legal fees recorded in 2016. The 2016 operating income also includes impairment of goodwill and intangible assets totaling $1.2 as described in Note 3, Asset Impairments, to the consolidated financial statements.

[4] Includes acquisition-related expenses of $10.1 for the year ended December 31, 2017.

[5] Includes restructuring costs of $15.6, $10.9 and $12.2 for the years ended December 31, 2017, 2016 and 2015, respectively

[6] During the third quarter of 2016, we recovered for breaches of representations and warranties primarily related to warranty costs for certain product lines acquired in the 2012 acquisition of AirSep under the related representation and warranty insurance. For the year ended December 31, 2016, this reduced BioMedical segment’s cost of sales by $15.2 and Corporate SG&A expenses by $0.3, net of associated legal fees recorded in 2016. The 2016 operating income also includes asset impairment charges of $1.2 attributed to D&S.

[7] Includes asset impairment charges of $255.1 for the year ended December 31, 2015, attributed to E&C – $68.8, D&S – $2.0, and BioMedical – $184.3.