Acquisitions - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Apr. 15, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Goodwill	$ 1,243,669		$ 1,206,877	$ 1,208,587
Opterna International Corp.
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Receivables	$ 5,300	$ 5,308
Inventory		7,470
Prepaid and other current assets		566
Property, plant, and equipment		1,328
Intangible assets		28,000
Goodwill		35,007
Deferred income taxes		69
Operating lease right-of-use assets		2,204
Other long-lived assets		2,070
Total assets acquired		82,022
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Accounts payable		4,847
Deferred revenue		4,346
Long-term debt		6,817
Long-term operating lease liability		1,923
Other long-term liabilities		7,153
Total liabilities assumed		25,086
Net assets		56,936
Noncontrolling interest		5,195
Net assets attributable to Belden		$ 51,741