Acquisitions - Summary of Allocation of Purchase Price Based on Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jul. 30, 2021	Dec. 31, 2020	Nov. 10, 2020
Assets acquired:
Goodwill	$ 89,250		$ 79,256
Trilogy Plastics, Inc. [Member]
Assets acquired:
Accounts receivable		$ 3,929
Inventories		2,669
Prepaid expenses		63
Other assets - long term		93
Property, plant and equipment		4,903
Right of use asset - operating leases		8,685
Intangible assets		14,333
Goodwill		10,036
Assets acquired		44,711
Liabilities assumed:
Accounts payable		765
Accrued expenses		727
Operating lease liability - short term		576
Operating lease liability - long term		8,108
Total liabilities assumed		10,176
Net acquisition cost		$ 34,535
Elkhart Plastics [Member]
Assets acquired:
Accounts receivable				$ 12,026
Inventories				13,639
Prepaid expenses				960
Other assets - long term				34
Property, plant and equipment				18,038
Right of use asset - operating leases				13,757
Intangible assets				16,627
Goodwill				12,243
Assets acquired				87,324
Liabilities assumed:
Accounts payable				5,603
Accrued expenses				4,623
Operating lease liability - short term				2,390
Operating lease liability - long term				10,867
Total liabilities assumed				23,483
Net acquisition cost				$ 63,841