Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Components of Other Comprehensive Income (Loss), Net of Tax (Details) $ in Thousands	9 Months Ended
	Sep. 30, 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	12,352
Ending balance	1,390,302
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	10,950
Amounts reclassified from accumulated other comprehensive income	0
Other comprehensive loss, net of tax	10,950
Ending balance	(58,741)
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	1,409
Other comprehensive loss, net of tax	1,409
Ending balance	(26,926)
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	10,950
Amounts reclassified from accumulated other comprehensive income	1,409
Other comprehensive loss, net of tax	12,359
Ending balance	$ (85,667)