Financial Information for the Company and Its Subsidiaries - Summarized Statements of Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Condensed Financial Statements, Captions [Line Items]
Revenue	$ 704,267				$ 616,653
Income before income taxes	85,643				79,312
Net income	66,558				61,910
Net income attributable to Acadia Healthcare Company, Inc.	$ 66,015	$ 61,124	$ 71,099	$ 80,079	$ 60,837