Accounts Receivable and Inventories (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2016
Accounts receivable
Trade accounts receivable	$ 344,268		$ 344,268		$ 251,013
Less: Allowance for doubtful accounts	(10,911)		(10,911)		(4,586)
Trade accounts receivable, net	333,357		333,357		246,427
Other receivables	53,019		53,019		53,770
Provision for doubtful accounts related to trade accounts receivable	5,433	$ (125)	5,423	$ (208)
Inventories
Finished goods	12,731		12,731		11,892
Work-in-process	14,447		14,447		20,839
Raw materials and purchased parts	80,432		80,432		61,547
Stores and supplies	26,280		26,280		21,907
Inventories	133,890		133,890		116,185
Inventory for Contracts
Loss provision that exceeds accumulated contract costs	6,600		6,600
Net customer advances	55,400		55,400		67,100
Contract estimated forward loss provision for Harsco Rail Segment					$ 1,800	$ 45,100
Revenues	350,898	339,907	680,800	664,347
SBB [Member]
Inventory for Contracts
Revenues	$ 5,900	$ 7,500	$ 10,600	$ 15,500
Contract 2 [Member] | SBB [Member]
Inventory for Contracts
Percentage complete	33.00%		33.00%
Harsco Environmental Segment
Accounts receivable
Provision for doubtful accounts related to trade accounts receivable	$ 5,400