Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) D Number_of_Visits	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Episode of care as episodic-based revenue, days | D			60
Percentage of total reimbursement of outlier payment			10.00%
Low utilization payment adjustment, maximum number of visits | Number_of_Visits			5
First threshold of therapy services required, visits | Number_of_Visits			6
Second threshold of services required, visits | Number_of_Visits			14
Third threshold of therapy services required, visits | Number_of_Visits			20
Historical collection rate from Medicare			99.00%
Episodes in progress that begin during reporting period, days | D			60
Hospice Medicare revenue rate accounted for routine care	99.00%	99.00%	98.00%	98.00%
Percentage of patient receivables outstanding			10.00%
Minimum days for accounts receivable outstanding to be fully reserved | D			365
Portion of accounts receivable derived from Medicare			58.00%		61.00%
Revenue adjustment to Medicare revenue	$ 5,000	$ 2,600	$ 8,400	$ 4,300
Rate of request for anticipated payment submitted for the initial episode of care			60.00%
Rate of request for anticipated payment submitted for subsequent episodes of care			50.00%
Maximum days to submit final bill from the start of episode | D			120
Maximum days to submit final bill from the date the request for anticipated payment was paid | D			60
Percentage Of Patient Receivables Outstanding Over Ten Percent	12.30%		12.30%
Stockholders Equity Including Portion Attributable To Noncontrolling Interest	$ 493,061		$ 493,061		$ 461,142
Tax benefit from stock options exercised and restricted stock vesting			0	$ 7,130
Accounting Standards Update 2016-09 [Member] | Net Income [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Tax benefit from stock options exercised and restricted stock vesting	2,900		3,100
Accounting Standards Update 2016-09 [Member] | Retained Earnings [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Stockholders Equity Including Portion Attributable To Noncontrolling Interest	400		$ 400
Home Health [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Historical collection rate from Medicare			99.00%
Hospice [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Historical collection rate from Medicare			99.00%
Cap Year Two Thousand Thirteen Through Two Thousand Sixteen [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Estimated amounts due back to Medicare					$ 800
Cap Year Two Thousand Thirteen Through Two Thousand Seventeen [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Estimated amounts due back to Medicare	$ 1,300		$ 1,300