Acquisitions - Other Acquisitions (Details) - USD ($) $ in Thousands	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 15, 2020	Feb. 27, 2020
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired						$ 0	$ 95,160
Goodwill	$ 299,040	$ 303,970				299,040		$ 303,970
Net sales	$ 222,420		$ 199,460			$ 648,140	$ 581,800
Affaba & Ferrari Srl [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired		$ 98,400
Goodwill										$ 49,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill										35,100
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Net Working Capital										9,400
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment										17,400
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities										$ 12,600
Net sales								$ 34,000
Rapak [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired				$ 11,400
Net sales									$ 30,000
RSA Engineered Products [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired					$ 83,700
Goodwill											$ 43,300
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill											36,900
Business Combination, Recognized Identifiable Assets and Liabilities Assumed, Net Working Capital											10,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment											2,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities											$ 8,700
Net sales									$ 30,000