Acquisitions and Divestitures (Divestitures Narrative) (Details) $ in Millions							3 Months Ended			6 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($) item	May 01, 2017 USD ($) item	Dec. 31, 2016 USD ($)	Sep. 03, 2016 USD ($) item	Feb. 01, 2016 USD ($) item	Jan. 01, 2016 USD ($) item	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses, Net of Cash Divested										$ 921	$ 12
Impairment of goodwill											1,400		$ 1,395
Impairment and (gain) loss on sale of businesses, net							$ 80	$ 1,639		330	1,656
Impairment of hospitals in discontinued operations							$ 5			5	$ 1
Goodwill, Written off Related to Disposal of Assets Held-for-Sale										$ 357
Williamson Memorial Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item	76						76			76
Lehigh Regional Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										Feb. 01, 2016
Number of licensed beds | item					88
Proceeds from Divestiture of Businesses, Net of Cash Divested					$ 11
Impairment and (gain) loss on sale of businesses, net														$ 4
Bartow Regional Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										Jan. 01, 2016
Number of licensed beds | item						72
Proceeds from Divestiture of Businesses, Net of Cash Divested						$ 60
Impairment and (gain) loss on sale of businesses, net														$ 5
McNairy Regional Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment and (gain) loss on sale of businesses, net									$ 7			$ 0
Alliance Health Blackwell [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										Sep. 03, 2016
Number of licensed beds | item				53
Impairment and (gain) loss on sale of businesses, net				$ 3
Home Care [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										Dec. 31, 2016
Percentage of ownership interest sold			80.00%											80.00%
Proceeds from Divestiture of Businesses, Net of Cash Divested			$ 128
Gain on sale														$ 91
Lake Area Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										Jun. 30, 2017
Number of licensed beds | item	88						88			88
Proceeds from Divestiture of Businesses, Net of Cash Divested	$ 32
Stringfellow Memorial Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										May 01, 2017
Number of licensed beds | item		125
Proceeds from Divestiture of Businesses, Net of Cash Divested		$ 14
Curae Health, Inc. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										May 01, 2017
Proceeds from Divestiture of Businesses, Net of Cash Divested		$ 32
Merit Health Gilmore Memorial [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		95
Merit Health Batesville [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		112
Steward Health, Inc. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										May 01, 2017
Proceeds from Divestiture of Businesses, Net of Cash Divested		$ 304
Easton Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		196
Sharon Regional Health System [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		258
Northside Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		355
Trumbull Memorial Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		311
Hillside Rehabilitation Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		69
Wuesthoff Health System - Rockledge [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		298
Wuesthoff Health System - Melbourne [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		119
Sebastian River Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item		154
AllianceHealth Pryor [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date										May 01, 2017
Number of licensed beds | item		52
Proceeds from Divestiture of Businesses, Net of Cash Divested		$ 1