Comprehensive Income and Accumulated Other Comprehensive Income (Loss) - Total Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 28, 2020	Mar. 29, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 28, 2020	Jun. 30, 2019
Equity [Abstract]
Net income (loss)	$ (67,881)	$ (11,219)	$ 42,290	$ 25,178	$ (79,100)	$ 67,468
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(44,671)		(16,904)		(22,881)	11,887
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	372		251		755	470
Total comprehensive income (loss)	(112,180)		25,637		(101,226)	79,825
Less: Comprehensive income (loss) attributable to noncontrolling interests	171		130		(9)	107
Comprehensive income (loss) attributable to Belden	$ (112,351)		$ 25,507		$ (101,217)	79,718
Foreign currency translation, tax income (loss)						$ 400