| Document and Entity Information | Aug. 08, 2019 |
| Document And Entity Information [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Aug. 8, 2019 |
| Entity Registrant Name | DIODES INC /DEL/ |
| Entity Central Index Key | 0000029002 |
| Entity Emerging Growth Company | false |
| Entity File Number | 002-25577 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 95-2039518 |
| Entity Address, Address Line One | 4949 Hedgcoxe Road |
| Entity Address, Address Line Two | Suite 200 |
| Entity Address, City or Town | Plano |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75024 |
| City Area Code | 972 |
| Local Phone Number | 987-3900 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | DIOD |
| Security Exchange Name | NASDAQ |
