Accounts Receivable and Inventories (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
Trade accounts receivable	$ 323,502	$ 251,013
Less: Allowance for doubtful accounts	(13,512)	(4,586)
Trade accounts receivable, net	309,990	246,427
Insurance claim receivable	0	30,000
Other receivables	21,265	23,770
Provision for doubtful accounts related to trade accounts receivable	7,507	380	$ 5,211
Inventories
Finished goods	14,550	11,892
Work-in-process	13,088	20,839
Raw materials and purchased parts	104,488	61,547
Stores and supplies	24,865	21,907
Total inventories	156,991	116,185
Valued at lower of cost or market:
LIFO basis	101,465	66,650
FIFO basis	7,473	5,719
Average cost basis	48,053	43,816
Total inventories	156,991	116,185
Excess of inventories valued at current costs over LIFO	0	23,000
Change in income as a result of LIFO basis inventory valuation over FIFO basis valuation	0	600	400
Provision for Loss on Contracts	6,400
Contract estimated forward loss provision for Harsco Rail Segment		1,800		$ 45,100
Revenues	1,503,742	1,347,672	1,307,470
SBB [Member]
Valued at lower of cost or market:
Revenues	$ 23,400	$ 24,200	$ 42,500
Contract 2 | SBB [Member]
Valued at lower of cost or market:
Percentage Complete	42.00%