| Document and Entity Information | Jun. 16, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Document Period End Date | Jun. 16, 2022 |
| Entity Registrant Name | KLDiscovery Inc. |
| Entity Central Index Key | 0001752474 |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity File Number | 001-38789 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 61-1898603 |
| Entity Address, Address Line One | 8201 Greensboro Dr. |
| Entity Address, Address Line Two | Suite 300 |
| Entity Address, City or Town | McLean |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 22102 |
| City Area Code | 703 |
| Local Phone Number | 288-3380 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Amendment Description | This Current Report on Form 8-K/A (this “Amendment”) amends the Current Report on Form 8-K of KLDiscovery, Inc. (the “Company”) filed with the U.S. Securities and Exchange Commission on June 17, 2022 (the “Original Form 8-K”) to report the final voting results of the Company’s 2022 annual meeting of stockholders held on June 17, 2022 (the “Annual Meeting”). The sole purpose of this Amendment is to adjust the formatting of the results reported in the Original Form 8-K for Proposals (ii) and (iii) as described below to read correctly. No other changes have been made to the Original Form 8-K. |
