Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss), Net of Tax (Detail) $ in Thousands	6 Months Ended
	Jul. 02, 2017 USD ($)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 1,461,317
Other comprehensive loss, net of tax	(26,169)
Ending balance	1,479,103
Foreign Currency Translation Component
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(4,661)
Other comprehensive loss attributable to Belden before reclassifications	(26,895)
Amounts reclassified from accumulated other comprehensive income (loss)	0
Other comprehensive loss, net of tax	(26,895)
Ending balance	(31,556)
Pension and Other Postretirement Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(34,406)
Other comprehensive loss attributable to Belden before reclassifications	0
Amounts reclassified from accumulated other comprehensive income (loss)	774
Other comprehensive loss, net of tax	774
Ending balance	(33,632)
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(39,067)
Other comprehensive loss attributable to Belden before reclassifications	(26,895)
Amounts reclassified from accumulated other comprehensive income (loss)	774
Other comprehensive loss, net of tax	(26,121)
Ending balance	$ (65,188)