Significant Accounting Policies - Percentage of Net Service Revenue Contributed from Each Reporting Segment (Detail) - Sales Revenue, Segment	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Health Care Organization, Revenue [Abstract]
Percentage of net service revenue	100.00%	100.00%	100.00%	100.00%
Home health services
Health Care Organization, Revenue [Abstract]
Percentage of net service revenue	76.00%	76.50%	76.20%	77.20%
Hospice services
Health Care Organization, Revenue [Abstract]
Percentage of net service revenue	9.40%	9.10%	9.10%	9.10%
Community-based services
Health Care Organization, Revenue [Abstract]
Percentage of net service revenue	5.20%	4.80%	5.10%	3.40%
Facility- based services
Health Care Organization, Revenue [Abstract]
Percentage of net service revenue	9.40%	9.60%	9.60%	10.30%