Acquisitions - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Jan. 29, 2021	Dec. 31, 2020	Dec. 31, 2019	Apr. 15, 2019
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Goodwill	$ 1,152,472		$ 1,251,938	$ 1,243,669
OTN Systems
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Receivables	$ 6,000				$ 6,009
Inventories					10,731
Other current assets					768
Property, plant, and equipment					602
Intangible assets		$ 39,930			39,930
Goodwill		41,749			41,749
Operating lease right-of-use assets					4,144
Other long-lived assets					416
Total assets acquired					104,349
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Accounts payable					6,884
Accrued liabilities					8,735
Long-term debt		$ 1,800			1,841
Postretirement benefits					3,581
Deferred income taxes					2,980
Long-term operating lease liabilities					3,271
Other long-term liabilities					3,692
Total liabilities assumed					30,984
Net assets					73,365
Noncontrolling interests					20
Net assets attributable to Belden					$ 73,345