Quarterly Results - Additional Information (Detail) (USD $)	3 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2013
Implementation of EHR applications
Quarterly Financial Information [Line Items]
Unfavorable pre-tax reduction	$ 7,900,000	$ 7,100,000	$ 8,900,000	$ 8,900,000	$ 1,100,000
Unfavorable after-tax reduction	4,500,000	3,900,000	4,900,000	4,900,000	327,000
Tax reduction per diluted share	$ 0.04	$ 0.04	$ 0.05	$ 0.05	$ 0.01
EHR applications
Quarterly Financial Information [Line Items]
Tax reduction per diluted share						$ 0.08	$ 0.12	$ 0.05
Favorable pre-tax reduction						13,800,000	19,400,000	8,400,000
Favorable after-tax reduction						8,600,000	11,800,000	5,100,000
Resulting from the gain realized on the sale of a non-operating investment
Quarterly Financial Information [Line Items]
Tax reduction per diluted share			$ 0.07
Favorable pre-tax reduction			10,100,000
Favorable after-tax reduction			6,300,000
Related to extinguishment of debt from the early redemption of previously outstanding $250 million 7.00% senior unsecured notes and the repayment of $550 million of previously outstanding Term Loan B facility
Quarterly Financial Information [Line Items]
Unfavorable pre-tax reduction	36,200,000
Unfavorable after-tax reduction	22,700,000
Tax reduction per diluted share	$ 0.23
Incurred in connection with the previously disclosed $65 million settlement of the Garden City matter
Quarterly Financial Information [Line Items]
Unfavorable pre-tax reduction	44,000,000
Unfavorable after-tax reduction	27,600,000
Tax reduction per diluted share	$ 0.27
Professional and general liability self-insurance reserves
Quarterly Financial Information [Line Items]
Tax reduction per diluted share				$ 0.38		$ 0.12	$ 0.09
Favorable pre-tax reduction				65,000,000		19,700,000	15,600,000
Favorable after-tax reduction				$ 37,800,000		$ 11,700,000	$ 9,200,000