Revenue - Schedule of Revenue and Percentage Generated by Each Payor Type (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Revenue, Major Customer [Line Items]
Revenue	$ 851,573	$ 815,634	$ 2,491,310	$ 2,379,725
U.S. Facilities [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 851,573	$ 815,634	$ 2,491,310	$ 2,379,725
Revenue, Percentage	100.00%	100.00%	100.00%	100.00%
U.S. Facilities [Member] \| Commercial [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 211,879	$ 216,050	$ 613,634	$ 621,702
Revenue, Percentage	24.90%	26.50%	24.60%	26.10%
U.S. Facilities [Member] \| Medicare [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 125,542	$ 118,022	$ 359,801	$ 339,117
Revenue, Percentage	14.70%	14.50%	14.40%	14.30%
U.S. Facilities [Member] \| Medicaid [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 484,171	$ 454,319	$ 1,431,374	$ 1,343,081
Revenue, Percentage	56.90%	55.70%	57.50%	56.40%
U.S. Facilities [Member] \| Self-Pay [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 17,809	$ 14,824	$ 48,672	$ 44,764
Revenue, Percentage	2.10%	1.80%	2.00%	1.90%
U.S. Facilities [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue	$ 12,172	$ 12,419	$ 37,829	$ 31,061
Revenue, Percentage	1.40%	1.50%	1.50%	1.30%

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details

Acadia Healthcare Company, Inc. 10-Q