Accounts Receivable - Schedule of Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Apr. 06, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 409,928		$ 323,502
Less: Allowance for expected credit losses and doubtful accounts (a) (b)	(8,934)		(13,512)
Trade accounts receivable, net	400,994		309,990
Other receivables	38,325		$ 21,265
ESOL | Harsco Clean Earth Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivables, before allowance for credit losses	136,200
Trade accounts receivable, net	123,200	$ 124,100
Accounts receivable, allowance for credit loss	$ 13,000