| Document And Entity Information | Jul. 31, 2024 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Acadia Healthcare Company, Inc. |
| Document, Type | 8-K |
| Document, Period End Date | Jul. 31, 2024 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 001-35331 |
| Entity, Tax Identification Number | 45-2492228 |
| Entity, Address, Address Line One | 6100 Tower Circle, Suite 1000 |
| Entity, Address, City or Town | Franklin |
| Entity, Address, State or Province | TN |
| Entity, Address, Postal Zip Code | 37067 |
| City Area Code | 615 |
| Local Phone Number | 861-6000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | ACHC |
| Security Exchange Name | NASDAQ |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001520697 |
