Employee Benefit Plans (Details 3) - Pension Plan $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) market shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($)
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Expected long-term rates of return on plan assets for next year (as a percent)		4.70%
Expected long-term rates of return on plan assets		5.10%	5.60%	5.90%
International, Other Than United Kingdom [Member]
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Pension plan assets as a percentage of international plan assets		4.00%
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation		$ 277,000	$ 296,700
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation		277,000	296,700
Accumulated benefit obligation		277,000	296,700
Fair value of plan assets		$ 232,900	$ 226,100
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Number of capital market results simulated in the model for expected return on plan assets | market		1,000
Period for which results of capital markets are simulated		20 years
Expected long-term rates of return on plan assets for next year (as a percent)		6.30%
Expected long-term rates of return on plan assets		6.80%	7.00%	7.30%
Number of shares of Company's common stock included in plan assets | shares		310,000	330,000
Fair values of plan assets		$ 232,947	$ 226,125	$ 226,268
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 232,947	226,125	226,268
Employer contributions		4,219	3,528
Fair value of plan assets at end of year		$ 232,947	$ 226,125	$ 226,268
U.S. Plans | Forecast
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Expected long-term rates of return on plan assets	6.30%
U.S. Plans | Domestic equity securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		22.80%	30.80%
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 5,180	$ 5,934
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 5,180	5,934
Fair value of plan assets at end of year		$ 5,180	5,934
U.S. Plans | Domestic equity securities | Minimum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		18.00%
U.S. Plans | Domestic equity securities | Maximum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		28.00%
U.S. Plans | Domestic mutual funds—equities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 48,411	63,651
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	48,411	63,651
Fair value of plan assets at end of year		$ 48,411	$ 63,651
U.S. Plans | International equity securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		22.50%	26.50%
U.S. Plans | International equity securities | Minimum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		17.00%
U.S. Plans | International equity securities | Maximum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		27.00%
U.S. Plans | International equities—mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 50,783	$ 59,933
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	50,783	59,933
Fair value of plan assets at end of year		$ 50,783	$ 59,933
U.S. Plans | Harsco common stock
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		2.20%	2.60%
U.S. Plans | Fixed income securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		45.90%	33.40%
U.S. Plans | Fixed income securities | Minimum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		41.00%
U.S. Plans | Fixed income securities | Maximum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		51.00%
U.S. Plans | Mutual funds - bonds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 105,114	$ 75,441
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	105,114	75,441
Fair value of plan assets at end of year		$ 105,114	$ 75,441
U.S. Plans | Other
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		8.80%	8.60%
U.S. Plans | Other | Minimum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		4.00%
U.S. Plans | Other | Maximum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		14.00%
U.S. Plans | Other mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 9,371	$ 8,944
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	9,371	8,944
Fair value of plan assets at end of year		$ 9,371	$ 8,944
U.S. Plans | Cash and cash equivalents
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		0.00%	0.70%
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 1,624	$ 1,691
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	1,624	1,691
Fair value of plan assets at end of year		$ 1,624	1,691
U.S. Plans | Cash and cash equivalents | Maximum
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		5.00%
U.S. Plans | Partnership [Member]
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 12,464	10,531
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	12,464	10,531
Fair value of plan assets at end of year		12,464	10,531
U.S. Plans | Defined Benefit Plan, Equity Securities, Common Stock, Employer, Related Party [Member]
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Value of shares of Company's common stock included in plan assets		5,200	5,900
U.S. Plans | Level 1
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		220,483	215,594
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	220,483	215,594
Fair value of plan assets at end of year		220,483	215,594
U.S. Plans | Level 1 | Domestic equity securities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		5,180	5,934
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	5,180	5,934
Fair value of plan assets at end of year		5,180	5,934
U.S. Plans | Level 1 | Domestic mutual funds—equities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		48,411	63,651
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	48,411	63,651
Fair value of plan assets at end of year		48,411	63,651
U.S. Plans | Level 1 | International equities—mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		50,783	59,933
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	50,783	59,933
Fair value of plan assets at end of year		50,783	59,933
U.S. Plans | Level 1 | Mutual funds - bonds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		105,114	75,441
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	105,114	75,441
Fair value of plan assets at end of year		105,114	75,441
U.S. Plans | Level 1 | Other mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		9,371	8,944
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	9,371	8,944
Fair value of plan assets at end of year		9,371	8,944
U.S. Plans | Level 1 | Cash and cash equivalents
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		1,624	1,691
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	1,624	1,691
Fair value of plan assets at end of year		1,624	1,691
U.S. Plans | Level 1 | Partnership [Member]
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
U.S. Plans | Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		12,464	10,531
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	12,464	10,531
Fair value of plan assets at end of year		12,464	10,531
U.S. Plans | Fair Value Measured at Net Asset Value Per Share [Member] | Domestic equity securities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
U.S. Plans | Fair Value Measured at Net Asset Value Per Share [Member] | Domestic mutual funds—equities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
U.S. Plans | Fair Value Measured at Net Asset Value Per Share [Member] | International equities—mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
U.S. Plans | Fair Value Measured at Net Asset Value Per Share [Member] | Mutual funds - bonds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
U.S. Plans | Fair Value Measured at Net Asset Value Per Share [Member] | Other mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
U.S. Plans | Fair Value Measured at Net Asset Value Per Share [Member] | Cash and cash equivalents
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
U.S. Plans | Fair Value Measured at Net Asset Value Per Share [Member] | Partnership [Member]
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		12,464	10,531
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	12,464	10,531
Fair value of plan assets at end of year		12,464	10,531
International Plans
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation		1,016,100	1,113,400
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Projected benefit obligation		988,600	1,115,700
Accumulated benefit obligation		984,700	1,109,800
Fair value of plan assets		$ 939,300	$ 953,500
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Expected long-term rates of return on plan assets for next year (as a percent)		4.40%
Expected long-term rates of return on plan assets		4.70%	5.20%	5.50%
Fair values of plan assets		$ 973,252	$ 957,177	$ 860,321
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	973,252	957,177	860,321
Employer contributions		25,077	21,955
Fair value of plan assets at end of year		$ 973,252	$ 957,177	$ 860,321
International Plans | Equity Securities [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		27.90%	32.00%
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		26.50%
International Plans | Mutual funds - equities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 271,811	$ 306,959
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	271,811	306,959
Fair value of plan assets at end of year		$ 271,811	$ 306,959
International Plans | Fixed income securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		63.60%	49.50%
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		65.50%
International Plans | Mutual funds - bonds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 613,243	$ 467,285
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	613,243	467,285
Fair value of plan assets at end of year		613,243	467,285
International Plans | Insurance contracts
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		5,684	6,282
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	5,684	6,282
Fair value of plan assets at end of year		$ 5,684	$ 6,282
International Plans | Other
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		7.80%	18.30%
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		8.00%
International Plans | Other mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		$ 75,651	$ 174,921
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	75,651	174,921
Fair value of plan assets at end of year		$ 75,651	$ 174,921
International Plans | Cash and cash equivalents
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets at December 31		0.70%	0.20%
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Target Long-Term Allocation (less than 5% for Cash and cash equivalents)		0.00%
Fair values of plan assets		$ 6,863	$ 1,730
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	6,863	1,730
Fair value of plan assets at end of year		6,863	1,730
International Plans | Level 1
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		6,863	1,730
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	6,863	1,730
Fair value of plan assets at end of year		6,863	1,730
International Plans | Level 1 | Mutual funds - equities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
International Plans | Level 1 | Mutual funds - bonds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
International Plans | Level 1 | Insurance contracts
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
International Plans | Level 1 | Other mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year		0	0
International Plans | Level 1 | Cash and cash equivalents
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		6,863	1,730
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	6,863	1,730
Fair value of plan assets at end of year		6,863	1,730
International Plans | Level 2
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		966,389	955,447
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	966,389	955,447
Fair value of plan assets at end of year		966,389	955,447
International Plans | Level 2 | Mutual funds - equities
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		271,811	306,959
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	271,811	306,959
Fair value of plan assets at end of year		271,811	306,959
International Plans | Level 2 | Mutual funds - bonds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		613,243	467,285
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	613,243	467,285
Fair value of plan assets at end of year		613,243	467,285
International Plans | Level 2 | Insurance contracts
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		5,684	6,282
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	5,684	6,282
Fair value of plan assets at end of year		5,684	6,282
International Plans | Level 2 | Other mutual funds
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		75,651	174,921
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	75,651	174,921
Fair value of plan assets at end of year		75,651	174,921
International Plans | Level 2 | Cash and cash equivalents
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Fair values of plan assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 0	0
Fair value of plan assets at end of year		$ 0	$ 0
United Kingdom
Defined Benefit Plan, Plan Assets, Allocations [Abstract]
Expected long-term rates of return on plan assets for next year (as a percent)		4.30%	4.70%
Pension plan assets as a percentage of international plan assets		96.00%