| Document and Entity Information | Jan. 10, 2020 |
| Cover [Abstract] | |
| Entity Incorporation State Country Code | DE |
| Amendment Flag | false |
| Entity Central Index Key | 0001068875 |
| Document Type | 8-K |
| Document Period End Date | Jan. 10, 2020 |
| Entity Registrant Name | BLUCORA, INC. |
| Entity File Number | 000-25131 |
| Entity Tax Identification Number | 91-1718107 |
| Entity Address, Address Line One | 6333 North State Highway 161 |
| Entity Address, Address Line Two | 4th Floor |
| Entity Address, City or Town | Irving |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75038 |
| City Area Code | (972) |
| Local Phone Number | 870-6400 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.0001 per share |
| Trading Symbol | BCOR |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
