Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Summary of Effects of Reclassifications from Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 04, 2021	Mar. 29, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	$ 36,621	$ 17,083
Income tax expense	(7,880)	(2,192)
Net income (loss) attributable to Belden stockholders	28,666	$ (11,189)
Reclassification out of Accumulated Other Comprehensive Income | Actuarial losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other nonoperating expense (income)	973
Reclassification out of Accumulated Other Comprehensive Income | Prior service cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other nonoperating expense (income)	28
Reclassification out of Accumulated Other Comprehensive Income | Pension and Other  Postretirement Benefit Plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	1,001
Income tax expense	(237)
Net income (loss) attributable to Belden stockholders	$ 764