Significant Accounting Policies - Percentage of Net Service Revenue Earned by Category of Payor (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Home health services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%	100.00%
Hospice services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%	100.00%
Home and community-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%	100.00%
Facility-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%	100.00%
HCI
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%	100.00%
Medicare | Home health services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	69.70%	72.00%	70.60%	72.20%
Medicare | Hospice services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	89.80%	88.40%	91.60%	90.50%
Medicare | Facility-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	59.30%	56.70%	56.60%	59.90%
Medicare | HCI
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	17.10%	16.80%	20.70%	21.10%
Medicaid | Home and community-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	21.80%	23.80%	23.70%	23.40%
Managed Care, Commercial, and Other | Home health services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	30.30%	28.00%	29.40%	27.80%
Managed Care, Commercial, and Other | Hospice services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	10.20%	11.60%	8.40%	9.50%
Managed Care, Commercial, and Other | Home and community-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	78.20%	76.20%	76.30%	76.60%
Managed Care, Commercial, and Other | Facility-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	40.70%	43.30%	43.40%	40.10%
Managed Care, Commercial, and Other | HCI
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	82.90%	83.20%	79.30%	78.90%