Goodwill and Other Intangible Assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Changes in carrying amounts of goodwill
Balance at December 31, 2016	$ 382,251
Foreign currency translation	17,665
Balance at September 30, 2017	399,916
Harsco Metals & Minerals Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2016	362,386
Foreign currency translation	17,665
Balance at September 30, 2017	380,051
Harsco Industrial Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2016	6,839
Foreign currency translation	0
Balance at September 30, 2017	6,839
Harsco Rail Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2016	13,026
Foreign currency translation	0
Balance at September 30, 2017	$ 13,026