Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss), Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jul. 01, 2018	Apr. 01, 2018	Jun. 30, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 1,431,329	$ 1,387,588	$ 1,292,146	$ 1,434,866	$ 1,387,588
Other comprehensive loss, net of tax	(16,653)	29,010	61,011	(31,392)
Ending balance	1,433,533	1,431,329	$ 1,351,110	$ 1,292,146	1,433,533
Foreign Currency Translation Component
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(41,882)			(41,882)
Other comprehensive income attributable to Belden before reclassifications					11,846
Amounts reclassified from accumulated other comprehensive income					0
Other comprehensive loss, net of tax					11,846
Ending balance	(30,036)				(30,036)
Pension and Other Postretirement Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(33,025)			(33,025)
Other comprehensive income attributable to Belden before reclassifications					0
Amounts reclassified from accumulated other comprehensive income					470
Other comprehensive loss, net of tax					470
Ending balance	(32,555)				(32,555)
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		$ (74,907)			(74,907)
Other comprehensive income attributable to Belden before reclassifications					11,846
Amounts reclassified from accumulated other comprehensive income					470
Other comprehensive loss, net of tax					12,316
Ending balance	$ (62,591)				$ (62,591)