Quarterly Results - Additional Information (Detail) - USD ($)	3 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017
Quarterly Financial Information [Line Items]
After tax reduction per diluted share pursuant to tax cuts and jobs act 2007					$ 30,000,000
After tax reduction per diluted share pursuant to tax cuts and jobs act 2007					$ 0.32
River Point Behavioral Health | Located in U.K.
Quarterly Financial Information [Line Items]
Unfavorable after tax reduction pursuant to tax cuts and jobs act 2007					$ 11,300,000
Tax reduction per diluted share pursuant to tax cuts and jobs act 2007					$ 0.12
River Point Behavioral Health | Located in Puerto Rico
Quarterly Financial Information [Line Items]
Unfavorable after tax reduction pursuant to tax cuts and jobs act 2007					$ 11,300,000
Tax reduction per diluted share pursuant to tax cuts and jobs act 2007					$ 0.12
EHR Applications
Quarterly Financial Information [Line Items]
Unfavorable pre-tax reduction					$ 3,600,000	$ 4,200,000	$ 6,400,000	$ 8,100,000
Unfavorable after-tax reduction					$ 2,300,000	$ 2,600,000	$ 4,000,000	$ 5,100,000
Tax reduction per diluted share					$ 0.03	$ 0.03	$ 0.04	$ 0.05
ASU 2016-09
Quarterly Financial Information [Line Items]
Favorable after tax impact				$ 1,600,000	$ 13,500,000	$ 487,000	$ 1,400,000	$ 6,800,000
Favorable after tax impact per share diluted				$ 0.02	$ 0.14	$ 0.01	$ 0.01	$ 0.07
DOJ Reserve
Quarterly Financial Information [Line Items]
Unfavorable pre-tax reduction	$ 31,900,000	$ 48,000,000	$ 9,500,000	$ 13,000,000
Unfavorable after-tax reduction	$ 24,500,000	$ 36,600,000	$ 7,200,000	$ 9,900,000
Tax reduction per diluted share	$ 0.26	$ 0.39	$ 0.08	$ 0.11
Provision for Intangible Asset Impairment
Quarterly Financial Information [Line Items]
Unfavorable pre-tax reduction	$ 49,300,000
Unfavorable after-tax reduction	$ 37,700,000
Tax reduction per diluted share	$ 0.41