| Cover | Nov. 02, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Document Period End Date | Nov. 2, 2020 |
| Entity Registrant Name | Coupa Software Inc |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-37901 |
| Entity Tax Identification Number | 20-4429448 |
| Entity Address, Address Line One | 1855 S. Grant Street |
| Entity Address, City or Town | San Mateo |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94402 |
| City Area Code | 650 |
| Local Phone Number | 931-3200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | COUP |
| Entity Emerging Growth Company | false |
| Amendment Flag | true |
| Entity Central Index Key | 0001385867 |
| Security Exchange Name | NASDAQ |
| Amendment Description | This Current Report on Form 8-K/A amends and supplements the Original Form 8-K to provide the disclosures required by Item 9.01(a) and 9.01(b) of Form 8-K, which were not previously filed with the Original Form 8-K, including the required historical financial information of Laurel Parent Holdings, Inc. and the required pro forma financial statements. Except as otherwise provided herein, the other disclosures made in the Original Form 8-K remain unchanged. |
