| Document and Entity Information | Oct. 24, 2019 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 24, 2019 |
| Entity Registrant Name | Power Integrations, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 000-23441 |
| Entity Tax Identification Number | 94-3065014 |
| Entity Address, Address Line One | 5245 Hellyer Avenue |
| Entity Address, City or Town | San Jose |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 95138-1002 |
| City Area Code | 408 |
| Local Phone Number | 414-9200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000833640 |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | POWI |
| Security Exchange Name | NASDAQ |
