Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Total Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Equity [Abstract]
Net income	$ 25,178	$ 2,570
Foreign currency translation gain (loss), net of $0.4 million and $0.5 million tax, respectively	28,791	(31,795)
Adjustments to pension and postretirement liability, net of $0.1 million and $0.3 million tax, respectively	219	403
Total comprehensive income (loss)	54,188	(28,822)
Less: Comprehensive loss attributable to noncontrolling interest	(23)	(32)
Comprehensive income (loss) attributable to Belden	54,211	(28,790)
Foreign currency translation, tax income (loss)	400	500
Adjustments to pension and postretirement liability, tax	$ 100	$ 300