| Document and Entity Information - shares | 3 Months Ended | |
| Mar. 31, 2018 | May 02, 2018 | |
| Document and Entity Information [Abstract] | ||
| Document Type | 10-Q | |
| Amendment Flag | false | |
| Document Period End Date | Mar. 31, 2018 | |
| Document Fiscal Year Focus | 2,018 | |
| Document Fiscal Period Focus | Q1 | |
| Trading Symbol | CRCM | |
| Entity Registrant Name | Care.com Inc | |
| Entity Central Index Key | 1,412,270 | |
| Current Fiscal Year End Date | --12-31 | |
| Entity Filer Category | Accelerated Filer | |
| Entity Common Stock, Shares Outstanding | 30,946,445 |
