Supplemental Condensed Consolidating Statements of Cash flows (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	$ 271,275	$ 194,639
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	(89,276)	(92,387)
Proceeds received from sale of assets and businesses	0	11,450
Acquisition of property and businesses	(34,500)	(3,301)
Costs incurred for purchase and implementation of electronic health records application	0	(6,504)
Net cash used in investing activities	(123,776)	(90,742)
Cash Flows from Financing Activities:
Reduction of long-term debt	(158,871)us-gaap_RepaymentsOfLongTermDebt	(109,054)us-gaap_RepaymentsOfLongTermDebt
Additional borrowings	20,800us-gaap_ProceedsFromLinesOfCredit	11,900us-gaap_ProceedsFromLinesOfCredit
Repurchase of common shares	(28,767)	(13,993)
Dividends paid	(9,899)us-gaap_PaymentsOfDividends	(4,933)us-gaap_PaymentsOfDividends
Issuance of common stock	1,768	1,445
Excess income tax benefits related to stock-based compensation	20,807	11,750
Profit distributions to noncontrolling interests	(2,413)	(1,989)
Proceeds received from sale/leaseback of real property	12,551	0
Changes in intercompany balances with affiliates, net	0	0
Net cash (used in) provided by financing activities	(144,024)	(104,874)
Effect of exchange rate changes on cash and cash equivalents	(466)	0
Decrease in cash and cash equivalents	3,009	(977)
Cash and cash equivalents, beginning of period	32,069	17,238
Cash and cash equivalents, end of period	35,078	16,261
Consolidating Adjustments
Condensed Financial Statements, Captions [Line Items]
Net cash 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
Acquisition of property and businesses	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
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
Decrease 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
Parent
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	62,343	70,888
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	0	0
Proceeds received from sale of assets and businesses		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	(156,097)	(97,975)
Additional borrowings	20,800	11,900
Repurchase of common shares	(28,767)	(13,993)
Dividends paid	(9,899)	(4,933)
Issuance of common stock	1,768	1,445
Excess income tax benefits related to stock-based compensation	20,807	11,750
Profit distributions to noncontrolling interests	0	0
Proceeds received from sale/leaseback of real property	0
Changes in intercompany balances with affiliates, net	89,045	20,918
Net cash (used in) provided by financing activities	(62,343)	(70,888)
Effect of exchange rate changes on cash and cash equivalents	0
Decrease 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 provided by operating activities	124,046	51,661
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	(59,217)	(70,385)
Proceeds received from sale of assets and businesses		11,450
Acquisition of property and businesses	(22,513)	0
Costs incurred for purchase and implementation of electronic health records application		(6,504)
Net cash used in investing activities	(81,730)	(65,439)
Cash Flows from Financing Activities:
Reduction of long-term debt	(2,561)	(228)
Additional borrowings	0	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	(45,555)	13,735
Net cash (used in) provided by financing activities	(48,116)	13,507
Effect of exchange rate changes on cash and cash equivalents	(466)
Decrease in cash and cash equivalents	(6,266)	(271)
Cash and cash equivalents, beginning of period	21,784	7,990
Cash and cash equivalents, end of period	15,518	7,719
Non Guarantors
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	84,886	72,090
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	(30,059)	(22,002)
Proceeds received from sale of assets and businesses		0
Acquisition of property and businesses	(11,987)	(3,301)
Costs incurred for purchase and implementation of electronic health records application		0
Net cash used in investing activities	(42,046)	(25,303)
Cash Flows from Financing Activities:
Reduction of long-term debt	(213)	(10,851)
Additional borrowings	0	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	(2,413)	(1,989)
Proceeds received from sale/leaseback of real property	12,551
Changes in intercompany balances with affiliates, net	(43,490)	(34,653)
Net cash (used in) provided by financing activities	(33,565)	(47,493)
Effect of exchange rate changes on cash and cash equivalents	0
Decrease in cash and cash equivalents	9,275	(706)
Cash and cash equivalents, beginning of period	10,285	9,248
Cash and cash equivalents, end of period	$ 19,560	$ 8,542

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3044-108585