| Cover | Mar. 26, 2024 |
| Entity Addresses [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 26, 2024 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 001-41013 |
| Entity Registrant Name | GCT Semiconductor Holding, Inc. |
| Entity Central Index Key | 0001851961 |
| Entity Tax Identification Number | 86-2171699 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 2290 North 1st Street |
| Entity Address, Address Line Two | Suite 201 |
| Entity Address, City or Town | San Jose |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 95131 |
| City Area Code | 408 |
| Local Phone Number | 434-6040 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Entity Information, Former Legal or Registered Name | Concord Acquisition Corp III |
| Common Stock [Member] | |
| Entity Addresses [Line Items] | |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | GCTS |
| Security Exchange Name | NYSE |
| Warrant [Member] | |
| Entity Addresses [Line Items] | |
| Title of 12(b) Security | Warrants, each whole warrant exercisable for one share of Common Stock for $11.50 per share |
| Trading Symbol | GCTSW |
| Security Exchange Name | NYSE |
| Former Address [Member] | |
| Entity Addresses [Line Items] | |
| Entity Address, Address Line One | 477 Madison Avenue |
| Entity Address, Address Line Two | 22nd Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10022 |
