Business Combinations - Textual (Details)		1 Months Ended	12 Months Ended
Business Combinations - Textual (Details)	Sep. 01, 2017	Apr. 30, 2015 USD ($) bed	Dec. 31, 2017 USD ($) state facilities	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Oct. 01, 2017 location	Aug. 01, 2017 location	Jul. 01, 2017 location	May 01, 2017 location	Apr. 08, 2017 bed	Apr. 01, 2017 bed	Feb. 01, 2017 location	Nov. 30, 2016 location	Oct. 31, 2016 location	Sep. 30, 2016 location	Aug. 31, 2016 bed	Jul. 31, 2016 location	May 31, 2016 location	Feb. 29, 2016 bed	Nov. 30, 2015 USD ($) facilities	Oct. 31, 2015 USD ($) hospital bed lease	May 31, 2015 bed	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Goodwill			$ 1,972,600,000	$ 1,927,200,000	$ 1,890,100,000																		$ 1,084,000,000
Increase in goodwill			$ 45,400,000	51,400,000	806,100,000
Number of states in which acquired entity operates \| state			36
Redeemable noncontrolling interests			$ 220,900,000	138,300,000
Inpatient Rehabilitation Segment [Member]
Business Acquisition [Line Items]
Goodwill			1,166,000,000	1,142,000,000	1,133,100,000																		491,500,000
Increase in goodwill			$ 24,000,000	8,900,000	641,600,000
Number of Joint Venture hospitals accounted for using equity method of accounting \| facilities			1
Number of states in which acquired entity operates \| state			31
Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Goodwill expected to be tax-deductible			$ 0
Increase in goodwill			24,000,000
Inpatient Rehabilitation Segment [Member] \| CHI St. Vincent Hot Springs [Member]
Business Acquisition [Line Items]
Interest acquired in business acquisition (percent)																			50.00%
Number of beds acquired \| bed																			20
Inpatient Rehabilitation Segment [Member] \| St. Joseph Regional Health Center (Bryan) [Member]
Business Acquisition [Line Items]
Interest acquired in business acquisition (percent)																50.00%
Number of beds acquired \| bed																19
Inpatient Rehabilitation Segment [Member] \| The Bernsen Rehabilitation Center at St. John (Broken Arrow) [Member]
Business Acquisition [Line Items]
Interest acquired in business acquisition (percent)																51.00%
Number of beds acquired \| bed																24
Inpatient Rehabilitation Segment [Member] \| Hot Springs, Bryan and Broken Arrow [Member]
Business Acquisition [Line Items]
Goodwill expected to be tax-deductible				0
Goodwill				9,400,000
Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Interest acquired in business acquisition (percent)		83.00%
Number of beds acquired \| bed		50
Goodwill expected to be tax-deductible		$ 0
Total current assets					10,100,000
Goodwill					$ 700,000
Increase in goodwill		$ 700,000
Inpatient Rehabilitation Segment [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Number of beds acquired \| bed																					902
Goodwill																					$ 642,600,000
Number of leases treated as capital leases \| lease																					7
Number of locations \| hospital																					11
Capital lease obligation																					$ 210,000,000
Remaining minority limited partner interest (percent)																					0.50%
Goodwill expected to be tax-deductible (percent)																					86.00%
Proforma tax rate (percent)					40.00%
Home Health and Hospice Segment [Member]
Business Acquisition [Line Items]
Goodwill			806,600,000	785,200,000	$ 757,000,000																		$ 592,500,000
Increase in goodwill			$ 21,400,000	42,500,000	164,500,000
Number of states in which acquired entity operates \| state			28
Home Health and Hospice Segment [Member] \| Celtic, Community, Bio Care, VNA, Ware, and Pickens County [Member]
Business Acquisition [Line Items]
Goodwill expected to be tax-deductible			$ 21,400,000
Total current assets			100,000
Goodwill			21,400,000
Increase in goodwill			21,400,000
Home Health and Hospice Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Goodwill expected to be tax-deductible				41,400,000	20,300,000
Goodwill			$ 41,400,000	$ 41,400,000	$ 20,300,000
Home Health and Hospice Segment [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Goodwill																				$ 143,300,000
Goodwill expected to be tax-deductible (percent)																				6.50%
Noncompete agreements [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					3 years
Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Hot Springs, Bryan and Broken Arrow [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life				$ 400,000
Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life					$ 100,000
Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life																					$ 9,700,000
Noncompete agreements [Member] \| Home Health and Hospice Segment [Member] \| Celtic, Community, Bio Care, VNA, Ware, and Pickens County [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			5 years
Identifiable intangible assets, Finite life			$ 800,000
Noncompete agreements [Member] \| Home Health and Hospice Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life				5 years
Identifiable intangible assets, Finite life				$ 1,100,000	$ 1,300,000
Noncompete agreements [Member] \| Home Health and Hospice Segment [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life																				$ 800,000
Trade names [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					1 year
Trade names [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					20 years
Trade names [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					5 years
Trade names [Member] \| Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			20 years
Trade names [Member] \| Inpatient Rehabilitation Segment [Member] \| Hot Springs, Bryan and Broken Arrow [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life				20 years
Identifiable intangible assets, Finite life				$ 1,000,000
Trade names [Member] \| Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					20 years
Identifiable intangible assets, Finite life					$ 800,000
Trade names [Member] \| Inpatient Rehabilitation Segment [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life																					8,900,000
Trade names [Member] \| Home Health and Hospice Segment [Member] \| Celtic, Community, Bio Care, VNA, Ware, and Pickens County [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			1 year
Identifiable intangible assets, Finite life			$ 100,000
Trade names [Member] \| Home Health and Hospice Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life				1 year
Identifiable intangible assets, Finite life				$ 700,000	$ 500,000
Trade names [Member] \| Home Health and Hospice Segment [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life																				2,800,000
Certificates of need [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					10 years
Certificates of need [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					20 years
Certificates of need [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					10 years
Certificates of need [Member] \| Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			20 years
Certificates of need [Member] \| Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					20 years
Identifiable intangible assets, Finite life					$ 8,800,000
Certificates of need [Member] \| Inpatient Rehabilitation Segment [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life																					36,600,000
Certificates of need [Member] \| Home Health and Hospice Segment [Member] \| Celtic, Community, Bio Care, VNA, Ware, and Pickens County [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			10 years
Identifiable intangible assets, Finite life			$ 1,800,000
Certificates of need [Member] \| Home Health and Hospice Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life				10 years
Identifiable intangible assets, Finite life				$ 1,900,000	$ 4,900,000
Certificates of need [Member] \| Home Health and Hospice Segment [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life																				15,600,000
Licenses [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					10 years
Licenses [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					20 years
Licenses [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					10 years
Licenses [Member] \| Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					20 years
Identifiable intangible assets, Finite life					$ 200,000
Licenses [Member] \| Inpatient Rehabilitation Segment [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life																					$ 11,400,000
Licenses [Member] \| Home Health and Hospice Segment [Member] \| Celtic, Community, Bio Care, VNA, Ware, and Pickens County [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			10 years
Identifiable intangible assets, Finite life			$ 4,000,000
Licenses [Member] \| Home Health and Hospice Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life				10 years
Identifiable intangible assets, Finite life				$ 3,400,000	$ 3,600,000
Licenses [Member] \| Home Health and Hospice Segment [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life																				$ 13,000,000
Maximum [Member] \| Noncompete agreements [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			18 years
Maximum [Member] \| Noncompete agreements [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					2 years
Maximum [Member] \| Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			3 years
Maximum [Member] \| Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Hot Springs, Bryan and Broken Arrow [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life				3 years
Maximum [Member] \| Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					3 years
Maximum [Member] \| Noncompete agreements [Member] \| Home Health and Hospice Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					2 years
Maximum [Member] \| Trade names [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			20 years
Maximum [Member] \| Certificates of need [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			30 years
Maximum [Member] \| Licenses [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			20 years
Minimum [Member] \| Noncompete agreements [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			1 year
Minimum [Member] \| Noncompete agreements [Member] \| Reliant [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					1 year
Minimum [Member] \| Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			2 years
Minimum [Member] \| Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Hot Springs, Bryan and Broken Arrow [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life				1 year
Minimum [Member] \| Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					2 years
Minimum [Member] \| Noncompete agreements [Member] \| Home Health and Hospice Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life					5 years
Minimum [Member] \| Trade names [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			1 year
Minimum [Member] \| Certificates of need [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			10 years
Minimum [Member] \| Licenses [Member]
Business Acquisition [Line Items]
Finite-lived intangible asset useful life			10 years
Inpatient [Member] \| Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Number of beds acquired \| bed																						158
Home health [Member] \| Home Health and Hospice Segment [Member] \| Celtic Healthcare of Maryland, Inc. [Member]
Business Acquisition [Line Items]
Number of locations \| location												2
Home health [Member] \| Home Health and Hospice Segment [Member] \| Community Health Services, Inc. [Member]
Business Acquisition [Line Items]
Number of locations \| location												2
Home health [Member] \| Home Health and Hospice Segment [Member] \| Bio Care Home Health Services and Kinsman Enterprises [Member]
Business Acquisition [Line Items]
Number of locations \| location									2
Home health [Member] \| Home Health and Hospice Segment [Member] \| VNA Healthtrends - IL, IN, AZ [Member]
Business Acquisition [Line Items]
Number of locations \| location								4
Home health [Member] \| Home Health and Hospice Segment [Member] \| VNA Healthtrends - OH and IL [Member]
Business Acquisition [Line Items]
Number of locations \| location							2
Home health [Member] \| Home Health and Hospice Segment [Member] \| Ware Visiting Nurses Services, Inc. [Member]
Business Acquisition [Line Items]
Number of locations \| location						1
Home health [Member] \| Home Health and Hospice Segment [Member] \| Pickens County Health Care Authority [Member]
Business Acquisition [Line Items]
Number of locations \| location						1
Home health [Member] \| Home Health and Hospice Segment [Member] \| Home Health Agency of Georgia, LLC [Member]
Business Acquisition [Line Items]
Number of locations \| location																		2
Home health [Member] \| Home Health and Hospice Segment [Member] \| Advantage Health Inc. [Member]
Business Acquisition [Line Items]
Number of locations \| location																	1
Home health [Member] \| Home Health and Hospice Segment [Member] \| Summit Home Health Care, Inc. [Member]
Business Acquisition [Line Items]
Number of locations \| location														2
Home health [Member] \| Home Health and Hospice Segment [Member] \| LightHouse Health Care, Inc. [Member]
Business Acquisition [Line Items]
Number of locations \| location														1
Home health [Member] \| Home Health and Hospice Segment [Member] \| Gulf City Home Care, Inc. [Member]
Business Acquisition [Line Items]
Number of locations \| location													1
Home health [Member] \| Home Health and Hospice Segment [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Number of locations \| facilities																				44
Hospice [Member] \| Home Health and Hospice Segment [Member] \| Home Health Agency of Georgia, LLC [Member]
Business Acquisition [Line Items]
Number of locations \| location																		2
Hospice [Member] \| Home Health and Hospice Segment [Member] \| Sotto International, Inc. [Member]
Business Acquisition [Line Items]
Number of locations \| location															3
Hospice [Member] \| Home Health and Hospice Segment [Member] \| Honor Hospice, LLC [Member]
Business Acquisition [Line Items]
Number of locations \| location													1
Hospice [Member] \| Home Health and Hospice Segment [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Number of locations \| facilities																				3
Skilled Nursing [Member] \| Inpatient Rehabilitation Segment [Member] \| Series of individually immaterial business acquisitions [Member]
Business Acquisition [Line Items]
Number of beds acquired \| bed																						74
Corporate Joint Venture [Member] \| Inpatient Rehabilitation Segment [Member] \| Memorial Hospital at Gulfport [Member]
Business Acquisition [Line Items]
Interest acquired in business acquisition (percent)											80.00%
Number of beds acquired \| bed											33
Corporate Joint Venture [Member] \| Inpatient Rehabilitation Segment [Member] \| Mount Carmel West [Member]
Business Acquisition [Line Items]
Interest acquired in business acquisition (percent)										80.00%
Number of beds acquired \| bed										60
Corporate Joint Venture [Member] \| Inpatient Rehabilitation Segment [Member] \| Jackson-Madison County General Hospital [Member]
Business Acquisition [Line Items]
Interest acquired in business acquisition (percent)								50.00%
Corporate Joint Venture [Member] \| Inpatient Rehabilitation Segment [Member] \| Heritage Valley Beaver Hospital [Member]
Business Acquisition [Line Items]
Interest acquired in business acquisition (percent)	75.00%
Interest exchanged in business acquisition (percent)	25.00%
Corporate Joint Venture [Member] \| Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Goodwill			$ 24,000,000
Corporate Joint Venture [Member] \| Noncompete agreements [Member] \| Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life			600,000
Corporate Joint Venture [Member] \| Trade names [Member] \| Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life			500,000
Corporate Joint Venture [Member] \| Certificates of need [Member] \| Inpatient Rehabilitation Segment [Member] \| Gulfport, Mount Carmel, Jackson and Heritage Valley [Member]
Business Acquisition [Line Items]
Identifiable intangible assets, Finite life			$ 9,800,000
Corporate Joint Venture [Member] \| Home health [Member] \| Home Health and Hospice Segment [Member] \| CareSouth [Member]
Business Acquisition [Line Items]
Number of Joint Venture hospitals accounted for using equity method of accounting \| facilities																				2