Acquisitions - Additional Information (Details) - USD ($)					3 Months Ended				6 Months Ended
	Apr. 15, 2019	Apr. 05, 2019	Apr. 25, 2018	Feb. 08, 2018	Jun. 30, 2019	Mar. 31, 2019	Jul. 01, 2018	Apr. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Business Acquisition [Line Items]
Purchase price, net of cash acquired									$ 50,517,000	$ 84,580,000
Severance, restructuring, and acquisition integration costs					$ 3,082,000		$ 24,928,000		6,860,000	45,322,000
Amortization of intangibles					22,368,000		25,039,000		45,709,000	49,457,000
Net income (loss)					42,290,000	$ 25,178,000	28,792,000	$ 2,570,000	67,468,000	31,362,000
Opterna International Corp.
Business Acquisition [Line Items]
Percentage of outstanding shares acquired	100.00%
Purchase price, net of cash acquired	$ 61,500,000
Acquisition price paid	45,500,000
Maximum earnout consideration	25,000,000.0
Estimated earnout consideration	16,000,000.0
Receivables	5,308,000
Property, plant, and equipment	1,328,000
Tax basis in acquired goodwill	$ 0
Post acquisition revenue of acquiree					8,800,000				8,800,000
Post acquisition income (loss) before taxes of acquiree					(100,000)				(100,000)
Net income attributable to Belden common stockholders					36,045,000		19,977,000		52,531,000	11,664,000
Amortization of intangibles					900,000				900,000
Inventory adjustment					600,000				600,000
Net income (loss)					$ 100,000				$ 100,000
Net-Tech Technology, Inc.
Business Acquisition [Line Items]
Percentage of outstanding shares acquired			100.00%
Acquisition price paid			$ 8,500,000
Snell Advanced Media
Business Acquisition [Line Items]
Percentage of outstanding shares acquired				100.00%
Acquisition Price				$ 104,600,000
Acquisition price paid				75,200,000
Maximum earnout consideration				31,400,000
Estimated earnout consideration				29,300,000
Long-term debt acquired				19,315,000
Receivables				16,551,000
Property, plant, and equipment				7,716,000
Tax basis in acquired goodwill				$ 0
Post acquisition revenue of acquiree							31,100,000			51,900,000
Post acquisition income (loss) before taxes of acquiree							(6,600,000)			(9,400,000)
Net income attributable to Belden common stockholders							35,241,000			34,169,000
Amortization of intangibles							2,800,000			5,000,000.0
Inventory adjustment							700,000			1,200,000
Suttle, Inc. Asset Acquisition
Business Acquisition [Line Items]
Asset acquisition, consideration transferred		$ 5,000,000
Severance and other restructuring costs | Snell Advanced Media
Business Acquisition [Line Items]
Net income attributable to Belden common stockholders							$ 20,300,000			$ 29,500,000