| Document and Entity Information | Jan. 12, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | ACORDA THERAPEUTICS INC |
| Amendment Flag | false |
| Entity Central Index Key | 0001008848 |
| Current Fiscal Year End Date | --12-31 |
| Document Type | 8-K |
| Document Period End Date | Jan. 12, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-31938 |
| Entity Tax Identification Number | 13-3831168 |
| Entity Address, Address Line One | 420 Saw Mill River Road |
| Entity Address, City or Town | Ardsley |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10502 |
| City Area Code | (914) |
| Local Phone Number | 347-4300 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.001 par value per share |
| Trading Symbol | ACOR |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
