Discontinued Operations - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of care centers closed	3	29	23
Home Health
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of care centers consolidated	5	27	59
Number of care centers exited	3
Number of care centers closed	3	27	19
Number of prospective unopened locations, start-up process discontinued		2	41
Hospice care center
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of care centers consolidated	4	5	3
Number of care centers closed		2	4
Number of prospective unopened locations, start-up process discontinued			6