Exit Activities - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restructuring Cost and Reserve [Line Items]
Number of care centers closed	3	29	23
Lease termination liabilities	$ 0.9
Severance payment	0.1
Discontinued operations liability	$ 0.2
Home Health
Restructuring Cost and Reserve [Line Items]
Number of care centers consolidated	5	27	59
Number of care centers closed	3	27	19
Number of prospective unopened locations, start-up process discontinued		2	41
Hospice care center
Restructuring Cost and Reserve [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