Income Per Share - Basis for Income Per Share Computations (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Numerator:
Income from continuing operations	$ 14,891	$ 27,935
Less: Net loss attributable to noncontrolling interest	(30)	(24)
Less: Preferred stock dividends	0	8,733
Income from continuing operations attributable to Belden common stockholders	14,921	19,226
Loss from discontinued operations, net of tax	(26,110)	(2,757)
Net income (loss) attributable to Belden common stockholders	$ (11,189)	$ 16,469
Denominator:
Weighted average shares outstanding, basic (in shares)	45,390	39,420
Effect of dilutive common stock equivalents (in shares)	148	240
Weighted average shares outstanding, diluted (in shares)	45,538	39,660