Summary of Significant Accounting Policies - Percentage of Net Service Revenue Earned by Category of Payor (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Home health
Significant Accounting Policies [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%
Home health | Medicare
Significant Accounting Policies [Line Items]
Percentage of net service revenue	62.10%	66.80%	70.20%
Home health | Managed Care, Commercial, and Other
Significant Accounting Policies [Line Items]
Percentage of net service revenue	37.90%	33.20%	29.80%
Hospice
Significant Accounting Policies [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%
Hospice | Medicare
Significant Accounting Policies [Line Items]
Percentage of net service revenue	94.20%	93.10%	92.00%
Hospice | Managed Care, Commercial, and Other
Significant Accounting Policies [Line Items]
Percentage of net service revenue	5.80%	6.90%	8.00%
Home and Community-Based
Significant Accounting Policies [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%
Home and Community-Based | Medicaid
Significant Accounting Policies [Line Items]
Percentage of net service revenue	31.50%	21.40%	23.20%
Home and Community-Based | Managed Care, Commercial, and Other
Significant Accounting Policies [Line Items]
Percentage of net service revenue	68.50%	78.60%	76.80%
Facility-Based
Significant Accounting Policies [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%
Facility-Based | Medicare
Significant Accounting Policies [Line Items]
Percentage of net service revenue	49.90%	55.00%	56.20%
Facility-Based | Managed Care, Commercial, and Other
Significant Accounting Policies [Line Items]
Percentage of net service revenue	50.10%	45.00%	43.80%
Healthcare Innovations
Significant Accounting Policies [Line Items]
Percentage of net service revenue	100.00%	100.00%	100.00%
Healthcare Innovations | Medicare
Significant Accounting Policies [Line Items]
Percentage of net service revenue	12.40%	19.20%	21.60%
Healthcare Innovations | Managed Care, Commercial, and Other
Significant Accounting Policies [Line Items]
Percentage of net service revenue	87.60%	80.80%	78.40%