Income Per Share - Basis for Income Per Share Computations (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Numerator:
Income from continuing operations	$ 3,173	$ 41,395	$ 18,064	$ 69,330
Less: Net income (loss) attributable to noncontrolling interest	24	90	(6)	66
Less: Preferred stock dividends	0	8,733	0	17,466
Income from continuing operations attributable to Belden common stockholders	3,149	32,572	18,070	51,798
Income (loss) from discontinued operations, net of tax	(71,054)	895	(97,164)	(1,862)
Net income (loss) attributable to Belden common stockholders	$ (67,905)	$ 33,467	$ (79,094)	$ 49,936
Denominator:
Weighted average shares outstanding, basic (in shares)	44,557	39,389	44,969	39,405
Effect of dilutive common stock equivalents (in shares)	108	222	128	230
Weighted average shares outstanding, diluted (in shares)	44,665	39,611	45,097	39,635