Information by Segment and Geographic Area (Details)	12 Months Ended
	Dec. 31, 2017 Customer segment	Dec. 31, 2016 Customer	Dec. 31, 2015 Customer
Revenue, Major Customer [Line Items]
Number of reportable segments | segment	3
Harsco Metals & Minerals
Revenue, Major Customer [Line Items]
Number of major customers	1	1	2
Harsco Industrial
Revenue, Major Customer [Line Items]
Number of major customers	1	0	2
Harsco Rail
Revenue, Major Customer [Line Items]
Number of major customers	1	1	2