| Document and Entity Information | Jan. 29, 2020 |
| Cover [Abstract] | |
| Entity Central Index Key | 0000863436 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 29, 2020 |
| Entity Registrant Name | BENCHMARK ELECTRONICS, INC. |
| Entity File Number | 1-10560 |
| Entity Incorporation, State or Country Code | TX |
| Entity Tax Identification Number | 74-2211011 |
| Entity Address, Address Line One | 56 South Rockford Drive |
| Entity Address, City or Town | Tempe |
| Entity Address, State or Province | AZ |
| Entity Address, Postal Zip Code | 85281 |
| City Area Code | 623 |
| Local Phone Number | 300-7000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.10 per share |
| Trading Symbol | BHE |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
