Acquisitions and Divestitures (Acquisitions Narrative) (Details) (USD $)	12 Months Ended			0 Months Ended								1 Months Ended	11 Months Ended
	Dec. 31, 2014 item	Dec. 31, 2013	Dec. 31, 2012	Nov. 03, 2014	Oct. 01, 2014	Apr. 01, 2014	Jul. 02, 2012	Mar. 05, 2012	Mar. 01, 2012	Jan. 01, 2012	Jan. 27, 2014	Jan. 27, 2014 item state	Dec. 31, 2014	Jan. 02, 2012 item
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs	$ 76,000,000	$ 21,000,000	$ 10,000,000
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Purchase of Interest by Parent	2,000,000	1,000,000	22,000,000
Business Acquisition, Purchase Price Allocation, Goodwill	8,951,000,000	4,424,000,000	4,388,000,000										8,951,000,000
Business Combination, Assumed Noncontrolling Interest, Fair Value	28,000,000	5,000,000											28,000,000
Business Combination Contingent Consideration Arrangements, Contingent Value Right, Amount Per Share	$ 1.00												$ 1.00
Number of States in which Entity Operates	28												28
Number of Hospitals Owned and Leased by the Company	197												197
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	360,000,000		337,000,000
Loss from early extinguishment of debt	73,000,000	1,000,000	115,000,000
Loss on Extinguishment of Debt, Net of Tax	45,000,000	1,000,000	72,000,000
Senior Secured Notes at 5.125, Due 2021 [Member] | Senior Secured Notes [Member]
Business Acquisition [Line Items]
Debt Instrument, Face Amount											1,000,000,000	1,000,000,000
Debt Instrument, Interest Rate, Stated Percentage											5.125%	5.125%
Senior Notes at 6.875, Due 2022 [Member] | Senior Notes [Member]
Business Acquisition [Line Items]
Debt Instrument, Face Amount											3,000,000,000	3,000,000,000
Debt Instrument, Interest Rate, Stated Percentage											6.875%	6.875%
Lake Norman [Member]
Business Acquisition [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Purchase of Interest by Parent				150,000,000
Business Acquisition, Percentage of Voting Interests Acquired				30.00%
Upstate Carolina Medical Center [Member]
Business Acquisition [Line Items]
Business Acquisition, Number of Licensed Hospital or Facility Beds				125
Business Acquisition, Cost of Acquired Entity, Purchase Price				4,000,000
Business Acquisition, Purchase Price Allocation, Goodwill	0												0
Novant [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Nov. 03, 2014
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities				5,000,000
Natchez Regional Medical Center [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Oct. 01, 2014
Business Acquisition, Number of Licensed Hospital or Facility Beds					179
Business Acquisition, Cost of Acquired Entity, Purchase Price					10,000,000
Prepayment of future property taxes					8,000,000
Period of prepayment for future property taxes will be applied to the tax liability					17 years
Business Acquisition, Purchase Price Allocation, Goodwill	0												0
Sharon Regional Health System [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Apr. 01, 2014
Business Acquisition, Number of Licensed Hospital or Facility Beds						258
Business Acquisition, Cost of Acquired Entity, Cash Paid for Fixed Assets						67,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid for Working Capital						1,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities						9,000,000
Business Acquisition, Cost of Acquired Entity, Purchase Price						77,000,000
Business Acquisition, Purchase Price Allocation, Goodwill	8,000,000												8,000,000
Munroe Regional Medical Center [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Apr. 01, 2014
Business Acquisition, Number of Licensed Hospital or Facility Beds						421
Business Acquisition, Cost of Acquired Entity, Cash Paid for Fixed Assets						192,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid for Working Capital						4,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities						11,000,000
Business Acquisition, Cost of Acquired Entity, Purchase Price						207,000,000
Business Acquisition, Purchase Price Allocation, Goodwill	11,000,000												11,000,000
Business Acquisition, Percentage of Voting Interests Acquired						95.00%
Business Combination, Assumed Noncontrolling Interest, Fair Value						10,000,000
Munroe Regional Medical Center [Member] | Affiliate of Regional Not-for-Profit Healthcare System [Member]
Business Acquisition [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners						5.00%
Memorial Health Systems [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Jul. 01, 2012
Business Acquisition, Number of Licensed Hospital or Facility Beds														100
Other Commitment														130,000,000
Business Acquisition, Maximum Number of Years for Completion of Replacement Hospital Construction	5 years
Business Acquisition, Cost of Acquired Entity, Cash Paid for Fixed Assets														45,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid for Working Capital														3,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities														13,000,000
Business Acquisition, Cost of Acquired Entity, Purchase Price							60,000,000
Business Acquisition, Purchase Price Allocation, Goodwill	11,000,000												11,000,000
Diagnostic Clinic of Longview [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Mar. 05, 2012
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities								7,000,000
Business Acquisition, Cost of Acquired Entity, Purchase Price								59,000,000
Business Acquisition, Purchase Price Allocation, Goodwill	42,000,000												42,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid								52,000,000
Metro South Medical Center [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Mar. 01, 2012
Business Acquisition, Number of Licensed Hospital or Facility Beds									330
Business Acquisition, Cost of Acquired Entity, Cash Paid for Fixed Assets									39,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid for Working Capital									(1,000,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities									6,000,000
Business Acquisition, Cost of Acquired Entity, Purchase Price									44,000,000
Business Acquisition, Purchase Price Allocation, Goodwill	0												0
Moses Taylor Healthcare [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Jan. 01, 2012
Business Acquisition, Number of Licensed Hospital or Facility Beds										217
Business Acquisition, Cost of Acquired Entity, Cash Paid for Fixed Assets										151,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid for Working Capital										13,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities										9,000,000
Business Acquisition, Cost of Acquired Entity, Purchase Price										174,000,000
Business Acquisition, Purchase Price Allocation, Goodwill	55,000,000												55,000,000
Business Acquisition, Number of Hospitals Acquired										2
Mid-Valley Hospital [Member]
Business Acquisition [Line Items]
Business Acquisition, Number of Licensed Hospital or Facility Beds										25
Health Management Associates, Inc. [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs	69,000,000
Business Acquisition, Effective Date of Acquisition	Jan. 27, 2014
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities											5,662,000,000	5,662,000,000
Business Acquisition, Cost of Acquired Entity, Purchase Price											3,531,000,000
Business Acquisition, Purchase Price Allocation, Goodwill											4,494,000,000	4,494,000,000
Business Combination, Assumed Noncontrolling Interest, Fair Value											335,000,000	335,000,000
Business Combination Consideration Transferred And Existing Indebtedness Assumed												7,300,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt											3,800,000,000	3,800,000,000
Payments to Acquire Businesses, Gross, Per Share												$ 10.50
Business Combination Consideration Transferred Equity Interests Issued, Per Share												0.06942
Business Combination Contingent Consideration Arrangements, Contingent Value Right, Number Per Share											1	1
Business Combination Contingent Consideration Arrangements, Contingent Value Right, Amount Per Share											$ 1.00	$ 1.00
Business Acquisition, Number of Hospitals Acquired											71	71
Number of States in which Entity Operates											15	15
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual													5,300,000,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual													564,000,000
Extinguishment of Debt, Gain (Loss), Per Share, Net of Tax	$ 0.40
Business Acquisition, Pro Forma Other Nonoperating Expense, Before Tax		133,000,000
Business Acquisition, Pro Forma Other Nonoperating Expense, Net of Tax		83,000,000
Business Acquisition, Pro Forma Earnings Per Share, Other Nonoperating Expense, Diluted		$ 0.74
Business Acquisition, Cost of Acquired Entity, Cash Paid											2,778,000,000
Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment											2,895,000,000	2,895,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill											112,000,000	112,000,000
Physician Practices Clinics and Other Ancillary Businesses [Member]
Business Acquisition [Line Items]
Business Combination, Assumed Noncontrolling Interest, Fair Value		5,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid	29,000,000	40,000,000	41,000,000
Business Acquisition, Purchase Price Allocation Net Working Capital			2,000,000
Business Acquisition, Purchase Price Allocation, Property, Plant and Equipment	15,000,000	9,000,000	10,000,000										15,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 14,000,000	$ 36,000,000	$ 33,000,000										$ 14,000,000