Nature of Operations Consolidation and Presentation of Financial Statements - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 States	Dec. 31, 2013	Dec. 31, 2012
Organization And Nature Of Operations [Line Items]
Percent Of Net Services Revenue Provided By Medicare	82.00%	84.00%	82.00%
Number Of States With Facilities	34
Minimum percent ownership for controlling interest percent	50.00%
Equity Method Investment Aggregate Cost	$ 18.8	$ 11.9
Cost Method Investments	5.0	5.0
Maximum Percent Ownership For Equity Method Percent	50.00%
Maximum Percent Ownership For Cost Method Percent	20.00%
Goodwill, Impairment Loss		(1.3)	(157.9)
Equity Method Investments [Member]
Organization And Nature Of Operations [Line Items]
Goodwill, Impairment Loss		1.3	17.4
Home Health [Member]
Organization And Nature Of Operations [Line Items]
Operating Care Centers	316
Goodwill, Impairment Loss		(1.3)	(157.9)
Hospice [Member]
Organization And Nature Of Operations [Line Items]
Operating Care Centers	80
Goodwill, Impairment Loss		$ 0	$ 0