Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) Group time PeriodicRate	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Disposal Group, Including Discontinued Operation, Goodwill	$ 1.5
License Leasing Arrangements	100.00%
Selected Medicare home health resource group | Group	1
Number of Medicare home health resource groups | Group	153
Number of days from date RAP paid to submit final Medicare bill	60 days
Low utilization adjustment visits | time	5
Minimum percentage of Medicare reimbursement from inpatient care services that subjects individual programs to inpatient cap	20.00%
Determination period for hospice Medicare inpatient reimbursement cap	12 months
Medicare credit risk for accounts receivable	55.00%
Reimbursement for initial episode of care	60.00%
Number of days from start of episode to submit final Medicare bill	120 days
Reimbursement for subsequent episodes of care	50.00%
Loss on impairment of intangible assets		$ 0.6
Depreciation expense	$ 13.4	$ 12.2	$ 12.0
Selected Hospice, Periodic Rate Used to Calculate Revenue | PeriodicRate	1
Number of Hospice, Periodic Rates Used to Calculate Revenue | PeriodicRate	4
Excess tax benefits, amount	$ 1.0
Current Fiscal Year End Date	--12-31
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible asset estimated useful life	2 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible asset estimated useful life	10 years
Building [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	39 years
Transportation, Furniture And Other Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	3 years
Transportation, Furniture And Other Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	10 years