Quarterly Results - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2012 Resulting from an agreement entered into with the United States Department of Health and Human Services, the Secretary of Health and Human Services, and the Centers for Medicare and Medicaid Services	Mar. 31, 2012 Oklahoma Supplemental Hospital Offset Payment Program	Jun. 30, 2013 Implementation of EHR applications	Mar. 31, 2013 Implementation of EHR applications	Jun. 30, 2012 Implementation of EHR applications	Mar. 31, 2012 Implementation of EHR applications	Mar. 31, 2012 Implementation of EHR applications Federal fiscal years 2006 through 2009	Jun. 30, 2012 Reimbursements related to prior years	Dec. 31, 2013 EHR applications	Sep. 30, 2013 EHR applications	Dec. 31, 2012 EHR applications	Sep. 30, 2012 EHR applications	Sep. 30, 2012 Write-off of deferred financing costs	Dec. 31, 2012 Sale of an acute care facility	Dec. 31, 2012 Professional and general liability self-insurance reserves relating to years prior to 2012	Dec. 31, 2013 Professional and general liability self-insurance reserves relating to years prior to 2013	Jun. 30, 2013 Professional and general liability self-insurance reserves relating to years prior to 2013
Quarterly Financial Information [Line Items]
Unfavorable pre-tax reduction			$ 8,900,000	$ 1,100,000	$ 8,000,000	$ 8,300,000	$ 2,400,000						$ 29,200,000
Unfavorable after-tax reduction			4,900,000	327,000	5,000,000	5,100,000							18,100,000
Tax reduction per diluted share	$ 0.19	$ 0.04	$ 0.05	$ 0.01	$ 0.05	$ 0.05		$ 0.03	$ 0.12	$ 0.05	$ 0.06	$ 0.01	$ 0.19	$ 0.17	$ 0.16	$ 0.09	$ 0.38
Favorable pre-tax reduction	30,200,000	7,000,000						5,500,000	19,400,000	8,400,000	8,900,000	2,200,000		26,400,000	27,200,000	15,600,000	65,000,000
Favorable after-tax reduction	18,800,000	4,300,000						3,400,000	11,800,000	5,100,000	5,500,000	1,300,000		16,400,000	15,500,000	9,200,000	37,800,000
Unfavorable after tax impact related to acute care hospital construction						$ 2,700,000