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Commitments and Contingencies (Details)			1 Months Ended		3 Months Ended				9 Months Ended		12 Months Ended
	Aug. 03, 2021	May 04, 2021 USD ($)	Dec. 31, 2020 USD ($) installment	Dec. 31, 2019 USD ($) weld	Sep. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) installment	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) claim	Sep. 30, 2020 USD ($)	Dec. 31, 2018 USD ($)	Jan. 01, 2020 USD ($)
Litigation
Accounts receivable, net			$ 107,628,000		$ 127,699,000		$ 107,628,000		$ 127,699,000
Contingency charges					0			$ (360,000)	1,030,000	$ (360,000)
Pension accrual			2,519,000		2,519,000		2,519,000		$ 2,519,000
Texas Customer
Litigation
Accounts receivable, net				$ 1,400,000
Litigation and Commercial Claims | Various Pipeline Projects for Texas Customer
Litigation
Amount of damages claimed				7,600,000
Litigation and Commercial Claims | Texas Customer
Litigation
Accounts receivable, net				$ 1,400,000
Number or welds not in compliance | weld				66
Number of welds inspected (over) | weld				16,000
Litigation and Commercial Claims | Texas Customer | Various Pipeline Projects for Texas Customer
Litigation
Amount of damages claimed				$ 1,400,000
Class Action
Litigation
Number of proceedings | claim									2
Settlement liability		$ 2,300,000
Contingency charges						$ 1,600,000	$ 800,000
Class Action on Behalf of Employees
Litigation
Number of proceedings | claim									1
Class Action on Behalf of State of California
Litigation
Number of proceedings | claim									1
Pension Related Contingencies
Litigation
Pension accrual					2,500,000				$ 2,500,000
Severance and Labor Disputes | Foreign Subsidiary | Brazil
Litigation
Settlement amount			$ 1,000,000
Number of settlement installments | installment			2				2
Percentage of settlement installments			0.31			0.69	0.31
Gain on settlement			$ 300,000			$ 600,000
Severance and Labor Disputes | Foreign Subsidiary | Right to Customer Contracts | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Germany
Litigation
Contingency charges									100,000
Consideration received on sale of subsidiary												$ 100,000
Payments of severance obligations									400,000
Reversal of severance obligations									1,000,000
Acquisition and Disposition Related Contingencies | Certain Acquired Companies
Litigation
Potential acquisition-related contingent consideration, low end of range					0				0
Potential acquisition-related contingent consideration, high end of range					2,800,000				$ 2,800,000
Contingent consideration payment period based upon achievement of specific performance metrics									12 months
Acquisition and Disposition Related Contingencies | Foreign Subsidiaries | Products and Systems | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Litigation
Term of agreement to purchase products from the buyer on sale of subsidiary											3 years
Amount of purchased commitment to buy products from the buyer on sale of subsidiary											$ 2,300,000
Remaining balance under purchase commitment agreement					$ 1,000,000				$ 1,000,000
Extension term under agreement to purchase products from buyer	12 months

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