Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (55,058)	$ (376,776)	$ 160,711
Foreign currency translation, net of tax of $1.0 million, $1.0 million, and $1.7 million, respectively	(112,562)	24,121	27,802
Adjustments to pension and postretirement liability, net of tax of $1.7 million, $1.1 million, and $1.0 million, respectively	(15,477)	(12,168)	(4,690)
Other comprehensive income (loss), net of tax	(128,039)	11,953	23,112
Comprehensive income (loss)	(183,097)	(364,823)	183,823
Less: Comprehensive income (loss) attributable to noncontrolling interest	498	703	(190)
Comprehensive income (loss) attributable to Belden	$ (183,595)	$ (365,526)	$ 184,013