Acquisitions - Schedule of Pro Forma Information (Details) - Opterna International Corp. - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Business Acquisition [Line Items]
Revenues	$ 548,352	$ 1,057,108
Net income from continuing operations attributable to Belden common stockholders	$ 35,150	$ 54,393
Diluted income from continuing operations per share attributable to Belden common stockholders	$ 0.89	$ 1.38