| Cover | Mar. 22, 2022 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0000707388 |
| Document Information [Line Items] | |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Address, Postal Zip Code | 06870 |
| Entity Address, Address Line One | 53 Forest Ave |
| Entity Address, City or Town | Old Greenwich |
| Entity Address, State or Province | CT |
| City Area Code | 203 |
| Local Phone Number | 489-9500 |
| Entity Registrant Name | Star Equity Holdings, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-35947 |
| Entity Tax Identification Number | 33-0145723 |
| Document Period End Date | Mar. 22, 2022 |
| Document Type | 8-K |
| Entity Address, Address Line Two | Suite 101 |
| Common Stock | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | STRR |
| Security Exchange Name | NASDAQ |
| Series A | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Series A Cumulative Perpetual Preferred Stock, par value $0.0001 per share |
| Trading Symbol | STRRP |
| Security Exchange Name | NASDAQ |
