CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 2,729	$ (21,975)	$ 512,218
Other comprehensive income (loss):
Foreign currency translation adjustments, net of deferred income taxes of $1,284, 2,507 and $(2,167) in 2020, 2019 and 2018, respectively	(10,994)	20,760	15,498
Net gain (loss) on cash flow hedging instruments, net of deferred income taxes of $(797), $79 and $1,438 in 2021, 2020 and 2019, respectively	2,816	(2,123)	(5,106)
Pension liability adjustments, net of deferred income taxes of $(5,409), $384 and $(3,244) in 2021, 2020 and 2019, respectively	92,252	(73,938)	(10,478)
Unrealized gain (loss) on marketable securities, net of deferred income taxes of $(12), $2 and $(11) in 2021, 2020 and 2019, respectively	31	(6)	28
Total OCI	84,105	(55,307)	(58)
Total comprehensive income (loss)	86,834	(77,282)	512,160
Less: Comprehensive income attributable to noncontrolling interests	(4,480)	(7,178)	(7,327)
Comprehensive income (loss) attributable to Harsco Corporation	$ 82,354	$ (84,460)	$ 504,833