Pension and Other Postretirement Benefits - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($) component	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined contribution expense	$ 16,600	$ 14,400	$ 14,000
Accumulated benefit obligation	$ 340,200	320,600
Defined benefit plan, plan assets, major components \| component	2
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Pension plans with projected benefit obligation in excess of plan assets, fair value of plan assets	$ 149,500	142,100
Pension plans with projected benefit obligation in excess of plan assets, accumulated benefit obligation	147,500	140,200
Pension plans with projected benefit obligation in excess of plan assets, projected benefit obligation	101,200	94,000
Settlement loss	27	1,147	(101)
Anticipated pension and other postretirement plans contributions, next fiscal year	$ 11,000
Pension Plan, Ongoing \| Minimum \| Defined Benefit Plan, Equity Securities, Asset Protection Investments
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations	45.00%
Pension Plan, Ongoing \| Minimum \| Defined Benefit Plan, Equity Securities, Asset Growth Investments
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations	50.00%
Pension Plan, Ongoing \| Maximum \| Defined Benefit Plan, Equity Securities, Asset Protection Investments
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations	50.00%
Pension Plan, Ongoing \| Maximum \| Defined Benefit Plan, Equity Securities, Asset Growth Investments
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations	55.00%
Pension Plan, Payment Or Terminated Vested Status \| Minimum \| Defined Benefit Plan, Equity Securities, Asset Protection Investments
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations	80.00%
Pension Plan, Payment Or Terminated Vested Status \| Minimum \| Defined Benefit Plan, Equity Securities, Asset Growth Investments
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations	5.00%
Pension Plan, Payment Or Terminated Vested Status \| Maximum \| Defined Benefit Plan, Equity Securities, Asset Protection Investments
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations	95.00%
Pension Plan, Payment Or Terminated Vested Status \| Maximum \| Defined Benefit Plan, Equity Securities, Asset Growth Investments
Defined Benefit Plan Disclosure [Line Items]
Target asset allocations	20.00%
Other Plans
Defined Benefit Plan Disclosure [Line Items]
Other postretirement plans with accumulated benefit obligation in excess of plan assets, accumulated benefit obligation	$ 19,800	19,500
Other postretirement plans with accumulated benefit obligation in excess of plan assets, fair value of plan assets	0	0
Settlement loss	0	$ 0	$ 0
Anticipated pension and other postretirement plans contributions, next fiscal year	$ 1,500

BELDEN INC. 10-K