| Cover Document | Apr. 29, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Apr. 29, 2021 |
| Entity Registrant Name | OMNICELL, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 000-33043 |
| Entity Tax Identification Number | 94-3166458 |
| Entity Address, Address Line One | 590 East Middlefield Road |
| Entity Address, City or Town | Mountain View |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94043 |
| City Area Code | 650 |
| Local Phone Number | 251-6100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 par value |
| Security Exchange Name | NASDAQ |
| Trading Symbol | OMCL |
| Entity Emerging Growth Company | false |
| Cover Non-printing | Apr. 29, 2021 |
| Cover [Abstract] | |
| Entity Central Index Key | 0000926326 |
| Amendment Flag | false |
