Goodwill and Intangible Assets - Goodwill Rollforward (Details) $ in Millions				3 Months Ended	9 Months Ended	12 Months Ended
	Oct. 01, 2020 USD ($) segment	Sep. 30, 2020 USD ($)	Jul. 01, 2019 segment	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($) segment
Goodwill
Beginning balance, goodwill	$ 817.6			$ 817.6	$ 811.4	$ 811.4	$ 487.2
Foreign currency translation adjustments and other				9.5	5.8
Goodwill acquired during the period				38.8			287.5
Purchase price adjustments					0.4		38.4
Ending balance, goodwill	817.6	$ 817.6		865.9	817.6	865.9	811.4
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	$ 129.0			129.0	129.0	129.0	129.0
Ending Balance, accumulated goodwill impairment loss		129.0		129.0	129.0	$ 129.0	$ 129.0
Number of reportable segments (segment) | segment	4					4	4
Adjustment
Goodwill Impaired
Number of reportable segments (segment) | segment			2
D&S East
Goodwill
Beginning balance, goodwill	$ 121.5			121.5	117.0	$ 117.0	$ 73.6
Goodwill, transfers		(121.5)
Foreign currency translation adjustments and other				0.0	4.5		(0.9)
Goodwill acquired during the period				0.0			0.0
Purchase price adjustments					0.0		44.3
Ending balance, goodwill	0.0	121.5		0.0	121.5	0.0	117.0
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	0.0			0.0	0.0	0.0	0.0
Ending Balance, accumulated goodwill impairment loss		0.0		0.0	0.0	0.0	0.0
D&S West
Goodwill
Beginning balance, goodwill	118.6			118.6	118.6	118.6	117.8
Goodwill, transfers		(118.6)
Foreign currency translation adjustments and other				0.0			0.0
Goodwill acquired during the period				0.0			0.0
Purchase price adjustments							0.8
Ending balance, goodwill	0.0	118.6		0.0	118.6	0.0	118.6
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	64.4			64.4	64.4	64.4	64.4
Goodwill Impaired Reallocation Amount				(64.4)
Ending Balance, accumulated goodwill impairment loss		64.4		0.0	64.4	0.0	64.4
E&C
Goodwill
Beginning balance, goodwill					0.0	0.0	295.8
Goodwill, transfers							(295.8)
Foreign currency translation adjustments and other							0.0
Goodwill acquired during the period							0.0
Purchase price adjustments							0.0
Ending balance, goodwill							0.0
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss					0.0	0.0	64.6
Ending Balance, accumulated goodwill impairment loss							0.0
E&C Cryogenics
Goodwill
Beginning balance, goodwill	176.2			176.2	176.2	176.2	0.0
Goodwill, transfers		(176.2)					183.5
Foreign currency translation adjustments and other				0.0			(0.6)
Goodwill acquired during the period				0.0			0.0
Purchase price adjustments							(6.7)
Ending balance, goodwill	0.0	176.2		0.0	176.2	0.0	176.2
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	40.9			40.9	40.9	40.9	0.0
Goodwill Impaired Reallocation Amount				(40.9)
Ending Balance, accumulated goodwill impairment loss		40.9		0.0	40.9	0.0	40.9
E&C FinFans
Goodwill
Beginning balance, goodwill	401.3			401.3	399.6	399.6	0.0
Goodwill, transfers		(401.3)					112.3
Foreign currency translation adjustments and other				0.0	1.3		(0.2)
Goodwill acquired during the period				0.0			287.5
Purchase price adjustments					0.4		0.0
Ending balance, goodwill	0.0	401.3		0.0	401.3	0.0	399.6
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	23.7			23.7	23.7	23.7	0.0
Goodwill Impaired Reallocation Amount				(23.7)
Ending Balance, accumulated goodwill impairment loss		23.7		0.0	23.7	0.0	23.7
Cryo Tank Solutions
Goodwill
Beginning balance, goodwill	0.0			0.0	0.0	0.0
Foreign currency translation adjustments and other				6.7
Goodwill acquired during the period				0.0
Ending balance, goodwill	86.5	0.0		93.2	0.0	93.2	0.0
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	0.0			0.0	0.0	0.0
Ending Balance, accumulated goodwill impairment loss		0.0		23.5	0.0	23.5	0.0
Cryo Tank Solutions | D&S East
Goodwill
Goodwill, transfers		43.3
Cryo Tank Solutions | D&S West
Goodwill
Goodwill, transfers		43.2
Goodwill Impaired
Goodwill Impaired Reallocation Amount				23.5
Heat Transfer Systems
Goodwill
Beginning balance, goodwill	0.0			0.0	0.0	0.0
Foreign currency translation adjustments and other				2.6
Goodwill acquired during the period				0.0
Ending balance, goodwill	432.6	0.0		435.2	0.0	435.2	0.0
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	0.0			0.0	0.0	0.0
Ending Balance, accumulated goodwill impairment loss		0.0		49.3	0.0	49.3	0.0
Heat Transfer Systems | Cryo Tank Solutions
Goodwill Impaired
Goodwill Impaired Reallocation Amount				31.8
Heat Transfer Systems | E&C Cryogenics
Goodwill
Goodwill, transfers		137.0
Heat Transfer Systems | E&C FinFans
Goodwill
Goodwill, transfers		295.6
Goodwill Impaired
Goodwill Impaired Reallocation Amount				17.5
Specialty Products
Goodwill
Beginning balance, goodwill	0.0			0.0	0.0	0.0
Foreign currency translation adjustments and other				(0.2)
Goodwill acquired during the period				38.8
Ending balance, goodwill	133.8	0.0		172.4	0.0	172.4	0.0
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	0.0			0.0	0.0	0.0
Ending Balance, accumulated goodwill impairment loss		0.0		35.8	0.0	35.8	0.0
Specialty Products | D&S East
Goodwill
Goodwill, transfers		64.6
Specialty Products | D&S West
Goodwill
Goodwill, transfers		63.6
Goodwill Impaired
Goodwill Impaired Reallocation Amount				34.5
Specialty Products | E&C Cryogenics
Goodwill
Goodwill, transfers		5.6
Goodwill Impaired
Goodwill Impaired Reallocation Amount				1.3
Repair, Service & Leasing
Goodwill
Beginning balance, goodwill	0.0			0.0	0.0	0.0
Foreign currency translation adjustments and other				0.4			(1.7)
Goodwill acquired during the period				0.0
Ending balance, goodwill	164.7	0.0		165.1	0.0	165.1	0.0
Goodwill Impaired
Beginning Balance, accumulated goodwill impairment loss	$ 0.0			0.0	0.0	0.0
Ending Balance, accumulated goodwill impairment loss		0.0		20.4	$ 0.0	$ 20.4	$ 0.0
Repair, Service & Leasing | D&S East
Goodwill
Goodwill, transfers		13.6
Repair, Service & Leasing | D&S West
Goodwill
Goodwill, transfers		11.8
Goodwill Impaired
Goodwill Impaired Reallocation Amount				6.4
Repair, Service & Leasing | E&C Cryogenics
Goodwill
Goodwill, transfers		33.6
Goodwill Impaired
Goodwill Impaired Reallocation Amount				7.8
Repair, Service & Leasing | E&C FinFans
Goodwill
Goodwill, transfers		$ 105.7
Goodwill Impaired
Goodwill Impaired Reallocation Amount				$ 6.2