Significant Accounting Policies - Percentage of Net Service Revenue Earned by Category of Payor (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 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	70.80%	72.90%	71.10%	72.30%
Medicare | Hospice services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	92.90%	91.10%	92.70%	91.70%
Medicare | Facility-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	53.00%	58.70%	55.20%	61.40%
Medicare | HCI
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	23.50%	26.70%	22.80%	26.70%
Medicaid | Home and community-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	24.30%	24.70%	24.70%	23.10%
Managed Care, Commercial, and Other | Home health services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	29.20%	27.10%	28.90%	27.70%
Managed Care, Commercial, and Other | Hospice services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	7.10%	8.90%	7.30%	8.30%
Managed Care, Commercial, and Other | Home and community-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	75.70%	75.30%	75.30%	76.90%
Managed Care, Commercial, and Other | Facility-based services
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	47.00%	41.30%	44.80%	38.60%
Managed Care, Commercial, and Other | HCI
Disaggregation of Revenue [Line Items]
Percentage of net service revenue	76.50%	73.30%	77.20%	73.30%