Estimated Useful Lives For Computing Depreciation Expense (Detail)	12 Months Ended
	Dec. 31, 2012
Buildings and building improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of asset	5 years
Buildings and building improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of asset	39 years
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of asset	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of asset	7 years
Medical equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of asset	3 years
Medical equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of asset	5 years
Other equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives of asset	3 years
Other equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives of asset	5 years