CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ 11,844	$ (79,753)	$ 6,332
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	121,839	129,083	144,652
Amortization	8,098	12,403	11,823
Change in fair value to the unit adjustment liability and loss on dilution and sale of equity method investment	0	58,494	8,491
Contract estimated forward loss provision for Harsco Rail Segment	0	45,050	0
Loss on early extinguishment of debt	2,265	35,337	0
Deferred income tax expense (benefit)	57,349	(7,654)	5,174
Equity in income of unconsolidated entities, net	0	(5,686)	(175)
Dividends from unconsolidated entities	93	16	28
Other, net	749	2,633	(5,740)
Changes in assets and liabilities, net of acquisitions and dispositions of businesses:
Accounts receivable	(32,012)	16,041	41,650
Inventories	19,557	(12,313)	(44,806)
Accounts payable	12,554	(20,194)	(136)
Accrued interest payable	438	(3,197)	(2,753)
Accrued compensation	11,126	8,865	(10,319)
Advances on contracts and other customer advances	(16,811)	14,485	(795)
Harsco 2011/2012 Restructuring Program accrual	0	0	(398)
Retirement plan liabilities, net	(21,300)	(20,420)	(24,593)
Other assets and liabilities	3,368	(13,314)	(6,663)
Net cash provided by operating activities	176,892	159,876	121,772
Cash flows from investing activities:
Purchases of property, plant and equipment	(98,314)	(69,340)	(123,552)
Proceeds from sales of assets	13,418	9,305	25,966
Net cash used to acquire businesses	0	(26)	(7,788)
Payment of unit adjustment liability	0	0	(22,320)
Proceeds from sale of equity investment	0	165,640	0
Net proceeds (payments) from settlement of foreign currency forward exchange contracts	(18,429)	17,238	(3,161)
Other investing activities, net	0	70	482
Net cash provided (used) by investing activities	(103,325)	122,887	(130,373)
Cash flows from financing activities:
Short-term borrowings, net	5,061	(2,350)	18,875
Current maturities and long-term debt:
Additions	27,985	720,727	427,996
Reductions	(108,280)	(979,567)	(399,533)
Cash dividends paid on common stock	0	(4,105)	(65,730)
Dividends paid to noncontrolling interests	(2,445)	(1,702)	(4,498)
Purchase of noncontrolling interests	(3,412)	(4,731)	(395)
Stock-based compensation - Employee taxes paid	(1,688)	(91)	(265)
Common stock acquired for treasury	0	0	(12,143)
Proceeds from cross-currency interest rate swap termination	0	16,625	75,057
Deferred pension underfunding payment to unconsolidated affiliate	0	(20,640)	(7,688)
Deferred financing costs	(42)	(16,530)	(9,487)
Other financing activities, net	(894)	0	0
Net cash provided (used) by financing activities	(83,715)	(292,364)	22,189
Effect of exchange rate changes on cash, including restricted cash	4,478	1,724	3,325
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(5,670)	(7,877)	16,913
Cash and cash equivalents, including restricted cash, at beginning of period	71,879	79,756	62,843
Cash and cash equivalents, including restricted cash, at end of period	66,209	71,879	79,756
Purchase of businesses, net of cash acquired
Working capital	0	0	(560)
Property, plant and equipment	0	0	(72)
Goodwill	0	0	(3,490)
Intangible Assets	0	0	(4,078)
Other noncurrent assets and liabilities, net	0	(26)	412
Net cash used to acquire businesses	$ 0	$ (26)	$ (7,788)