Other (Income) Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Income and Expenses [Abstract]
Employee termination benefit costs	$ 2,536	$ 1,790	$ 4,947	$ 8,756
Harsco Metals & Minerals Segment separation costs	0	1	0	3,298
Net gains	(4,821)	(608)	(4,815)	(1,365)
Other costs to exit activities	327	0	495	0
Impaired asset write-downs	539	0	820	0
Other	182	558	282	1,422
Other (income) expenses	$ (1,237)	$ 1,741	$ 1,729	$ 12,111