Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property Plant And Equipment [Abstract]
Land	$ 35,885us-gaap_Land	$ 34,960us-gaap_Land
Buildings	157,550us-gaap_BuildingsAndImprovementsGross	157,998us-gaap_BuildingsAndImprovementsGross
Leasehold improvements	2,002,735us-gaap_LeaseholdImprovementsGross	1,762,470us-gaap_LeaseholdImprovementsGross
Equipment and information systems	2,066,775us-gaap_MachineryAndEquipmentGross	1,839,981us-gaap_MachineryAndEquipmentGross
New center and capital asset projects in progress	235,660us-gaap_ConstructionInProgressGross	172,261us-gaap_ConstructionInProgressGross
Property, Plant and Equipment, Gross, Total	4,498,605us-gaap_PropertyPlantAndEquipmentGross	3,967,670us-gaap_PropertyPlantAndEquipmentGross
Less accumulated depreciation	(2,029,506)	(1,778,259)
Property and equipment, net	$ 2,469,099us-gaap_PropertyPlantAndEquipmentNet	$ 2,189,411us-gaap_PropertyPlantAndEquipmentNet

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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-Publisher SEC

-Name Regulation S-X (SX)

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-Section 02

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- Definition

Amount before accumulated depreciation of building structures held for productive use including addition, improvement, or renovation to the structure, including, but not limited to, interior masonry, interior flooring, electrical, and plumbing.

+ References

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

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- Definition

Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

+ References

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- Definition

Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-Subparagraph (SX 210.5-02.13)

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- Definition

Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

+ References

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- Definition

Amount before accumulated depreciation of tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment.

+ References

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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-Publisher FASB

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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