Acquisitions - Additional Information (Details) - USD ($)					3 Months Ended	9 Months Ended		12 Months Ended
	Dec. 06, 2019	Oct. 25, 2019	Apr. 15, 2019	Apr. 05, 2019	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019	Dec. 31, 2021
Business Acquisition [Line Items]
Purchase price, net of cash acquired						$ (590,000)	$ 50,951,000
Opterna International Corp.
Business Acquisition [Line Items]
Purchase price, net of cash acquired			$ 51,700,000
Percentage of outstanding shares acquired			100.00%
Acquisition price paid			$ 45,900,000
Maximum earnout consideration			25,000,000.0
Estimated earnout consideration			5,800,000
Noncontrolling interest, purchase price		$ 800,000
Payments to acquire interest in subsidiaries		$ 400,000
Receivables			5,308,000
Property, plant, and equipment			1,328,000
Tax basis in acquired goodwill			$ 0
Net income attributable to Belden common stockholders					$ 39,721,000		$ 91,459,000
Opterna International Corp. | Forecast
Business Acquisition [Line Items]
Payments to acquire interest in subsidiaries								$ 400,000
Special Product Compay
Business Acquisition [Line Items]
Purchase price, net of cash acquired	$ 22,500,000
Suttle, Inc. Asset Acquisition
Business Acquisition [Line Items]
Asset acquisition, consideration transferred				$ 5,000,000.0