Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Total contract assets	$ 57.6		$ 57.6		$ 31.2
Total advances on contracts	86.0		86.0		$ 60.3
Revenue recognized	20.0	$ 17.0	55.0	$ 53.0
Disaggregation of Revenue [Line Items]
Contract with Customer, Liability, Revenue Recognized	20.0	$ 17.0	$ 55.0	$ 53.0
Harsco Rail Segment
Revenue from Contract with Customer [Abstract]
Revenue recognized	0.8
Disaggregation of Revenue [Line Items]
Contract with Customer, Liability, Revenue Recognized	$ 0.8