| Document and Entity Information Document | Feb. 10, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Feb. 10, 2021 |
| Entity Registrant Name | Belden Inc. |
| Entity Central Index Key | 0000913142 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-12561 |
| Entity Tax Identification Number | 36-3601505 |
| Entity Address, Address Line One | 1 North Brentwood Boulevard |
| Entity Address, Address Line Two | 15th Floor |
| Entity Address, City or Town | St. Louis |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 63105 |
| City Area Code | 314 |
| Local Phone Number | 854-8000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock, $0.01 par value |
| Trading Symbol | BDC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
