Nature of Operations Consolidation and Presentation of Financial Statements - Additional Information (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) Agencies States	Sep. 30, 2014	Sep. 30, 2015 USD ($) Agencies States	Sep. 30, 2014	Dec. 31, 2014 USD ($)
Organization And Nature Of Operations [Line Items]
Percent Of Net Services Revenue Provided By Medicare	79.00%	81.00%	80.00%	82.00%
Number Of States With Facilities | States	34		34
Minimum percent ownership for controlling interest percent	50.00%		50.00%
Equity Method Investment Aggregate Cost	$ 24.4		$ 24.4		$ 18.8
Cost Method Investments	$ 0.0		$ 0.0		$ 5.0
Maximum Percent Ownership For Equity Method Percent	50.00%		50.00%
Maximum Percent Ownership For Cost Method Percent	20.00%		20.00%
Home Health [Member]
Organization And Nature Of Operations [Line Items]
Operating Care Centers | Agencies	314		314
Hospice [Member]
Organization And Nature Of Operations [Line Items]
Operating Care Centers | Agencies	79		79