Accounts Receivable (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Jan. 31, 2020	Jan. 01, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 425,808,000	$ 414,891,000
Accounts Receivable Greater than 12 Months Reserved	5,200,000
Receivable with Imputed Interest, Face Amount	$ 40,000,000.0
Note Receivable; Interest Rate; Stated percentage	2.50%
Receivables, Fair Value Disclosure	$ 36,200,000		$ 34,300,000	$ 34,300,000
Greater than 12 months
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 10,300,000
Harsco Industrial IKG | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Selling price				$ 85,000,000.0
Receivable with Imputed Interest, Face Amount			$ 40,000,000.0