Income Per Share - Basis for Income Per Share Computations (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Income from continuing operations	$ 2,530	$ 38,031	$ 41,395	$ 27,935	$ 35,965	$ 87,046	$ 40,278	$ 3,855	$ 109,891	$ 167,144	$ 102,607
Less: Net income (loss) attributable to noncontrolling interest	179	(6)	90	(24)	(35)	(23)	(77)	(48)	239	(183)	(357)
Less: Preferred stock dividends	0	971	8,733	8,733	8,733	8,732	8,733	8,733	18,437	34,931	34,931
Income from continuing operations attributable to Belden common stockholders									91,215	132,396	68,033
Loss from discontinued operations, net of tax	(149,759)	(335,046)	895	(2,757)	7,526	(1,188)	(11,486)	(1,285)	(486,667)	(6,433)	(9,754)
Net income (loss) attributable to Belden common stockholders	$ (147,408)	$ (297,980)	$ 33,467	$ 16,469	$ 34,793	$ 77,149	$ 20,136	$ (6,115)	$ (395,452)	$ 125,963	$ 58,279
Denominator:
Weighted average shares outstanding, basic (in shares)									42,203	40,675	42,220
Effect of dilutive common stock equivalents (in shares)									213	281	423
Weighted average shares outstanding, diluted (in shares)									42,416	40,956	42,643