Acquisitions and Disposals - Schedule of Aggregate Consideration Paid and Recognized Identified Assets Acquired and Liabilities Assumed (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Consideration
Cash	$ 22,445
Fair value of total consideration transferred	22,445
Acquisition-related costs (included in general and administrative expenses)	459
Recognized amounts of identifiable assets acquired and liabilities assumed
Other assets and (liabilities)	(135)
Total identifiable assets	1,945
Noncontrolling interest	608
Goodwill, including noncontrolling interest of $583	21,108
Trade Name [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Business acquisition, purchase price allocation, Intangible Assets	1,177
Certificate of need/license [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Business acquisition, purchase price allocation, Intangible Assets	627
Other identifiable intangible assets [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed
Business acquisition, purchase price allocation, Intangible Assets	$ 276