Supplemental Condensed Consolidating Statements of Cash flows (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ 796,499	$ 689,554
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	(269,578)	(309,361)
Proceeds received from sale of assets and businesses	2,744	15,178
Acquisition of property and businesses	(183,103)	(402,405)
Costs incurred for purchase and implementation of electronic health records application	0	(11,204)
Net cash used in investing activities	(449,937)	(707,792)
Cash Flows from Financing Activities:
Reduction of long-term debt	(207,371)	(842,543)
Additional borrowings	16,300	969,800
Financing costs	0	(13,413)
Repurchase of common shares	(129,862)	(63,292)
Dividends paid	(29,696)	(19,794)
Issuance of common stock	6,030	4,907
Excess income tax benefits related to stock-based compensation	29,287	30,242
Profit distributions to noncontrolling interests	(35,965)	(25,074)
Proceeds received from sale/leaseback of real property	12,765	0
Changes in intercompany balances with affiliates, net	0	0
Net cash (used in) provided by financing activities	(338,512)	40,833
Effect of exchange rate changes on cash and cash equivalents	(596)	(122)
Increase in cash and cash equivalents	7,454	22,473
Cash and cash equivalents, beginning of period	32,069	17,238
Cash and cash equivalents, end of period	39,523	39,711
Parent
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(51,998)	8,445
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	0	0
Proceeds received from sale of assets and businesses	0	0
Acquisition of property and businesses	0	0
Costs incurred for purchase and implementation of electronic health records application		0
Net cash used in investing activities	0	0
Cash Flows from Financing Activities:
Reduction of long-term debt	(203,284)	(830,680)
Additional borrowings	16,300	969,800
Financing costs		(13,413)
Repurchase of common shares	(129,862)	(63,292)
Dividends paid	(29,696)	(19,794)
Issuance of common stock	6,030	4,907
Excess income tax benefits related to stock-based compensation	29,287	30,242
Profit distributions to noncontrolling interests	0	0
Proceeds received from sale/leaseback of real property	0
Changes in intercompany balances with affiliates, net	363,223	(86,215)
Net cash (used in) provided by financing activities	51,998	(8,445)
Effect of exchange rate changes on cash and cash equivalents	0	0
Increase in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	0	0
Guarantors
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	554,650	431,986
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	(154,460)	(205,455)
Proceeds received from sale of assets and businesses	0	11,450
Acquisition of property and businesses	(171,116)	(394,854)
Costs incurred for purchase and implementation of electronic health records application		(11,204)
Net cash used in investing activities	(325,576)	(600,063)
Cash Flows from Financing Activities:
Reduction of long-term debt	(3,163)	(609)
Additional borrowings	0	0
Financing costs		0
Repurchase of common shares	0	0
Dividends paid	0	0
Issuance of common stock	0	0
Excess income tax benefits related to stock-based compensation	0	0
Profit distributions to noncontrolling interests	0	0
Proceeds received from sale/leaseback of real property	0
Changes in intercompany balances with affiliates, net	(219,165)	190,021
Net cash (used in) provided by financing activities	(222,328)	189,412
Effect of exchange rate changes on cash and cash equivalents	(596)	(122)
Increase in cash and cash equivalents	6,150	21,213
Cash and cash equivalents, beginning of period	21,784	7,990
Cash and cash equivalents, end of period	27,934	29,203
Non Guarantors
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	293,847	249,123
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	(115,118)	(103,906)
Proceeds received from sale of assets and businesses	2,744	3,728
Acquisition of property and businesses	(11,987)	(7,551)
Costs incurred for purchase and implementation of electronic health records application		0
Net cash used in investing activities	(124,361)	(107,729)
Cash Flows from Financing Activities:
Reduction of long-term debt	(924)	(11,254)
Additional borrowings	0	0
Financing costs		0
Repurchase of common shares	0	0
Dividends paid	0	0
Issuance of common stock	0	0
Excess income tax benefits related to stock-based compensation	0	0
Profit distributions to noncontrolling interests	(35,965)	(25,074)
Proceeds received from sale/leaseback of real property	12,765
Changes in intercompany balances with affiliates, net	(144,058)	(103,806)
Net cash (used in) provided by financing activities	(168,182)	(140,134)
Effect of exchange rate changes on cash and cash equivalents	0	0
Increase in cash and cash equivalents	1,304	1,260
Cash and cash equivalents, beginning of period	10,285	9,248
Cash and cash equivalents, end of period	11,589	10,508
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	0	0
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	0	0
Proceeds received from sale of assets and businesses	0	0
Acquisition of property and businesses	0	0
Costs incurred for purchase and implementation of electronic health records application		0
Net cash used in investing activities	0	0
Cash Flows from Financing Activities:
Reduction of long-term debt	0	0
Additional borrowings	0	0
Financing costs		0
Repurchase of common shares	0	0
Dividends paid	0	0
Issuance of common stock	0	0
Excess income tax benefits related to stock-based compensation	0	0
Profit distributions to noncontrolling interests	0	0
Proceeds received from sale/leaseback of real property	0
Changes in intercompany balances with affiliates, net	0	0
Net cash (used in) provided by financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Increase in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	$ 0	$ 0