CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
CONSOLIDATED STATEMENTS OF INCOME (Unaudited)
Provision for bad debts	$ 869	$ 990	$ 1,607	$ 1,629

Amount of the provision for bad debts related to patient service revenue.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 954

-SubTopic 605

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=9156363&loc=SL9156442-115640

Name:	us-gaap_HealthCareOrganizationPatientServiceRevenueProvisionforBadDebts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration