Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss), Net of Tax (Detail) $ in Thousands	6 Months Ended
	Jul. 01, 2018 USD ($)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 1,434,866
Other comprehensive loss, net of tax	29,619
Ending balance	1,351,110
Foreign Currency Translation Component
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(69,691)
Other comprehensive income attributable to Belden before reclassifications	28,848
Amounts reclassified from accumulated other comprehensive income	0
Other comprehensive loss, net of tax	28,848
Ending balance	(40,843)
Pension and Other Postretirement Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(28,335)
Other comprehensive income attributable to Belden before reclassifications	0
Amounts reclassified from accumulated other comprehensive income	772
Other comprehensive loss, net of tax	772
Ending balance	(27,563)
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(98,026)
Other comprehensive income attributable to Belden before reclassifications	28,848
Amounts reclassified from accumulated other comprehensive income	772
Other comprehensive loss, net of tax	29,620
Ending balance	$ (68,406)