Contingencies (Contingencies Narrative) (Details) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended
	Jan. 17, 2017 USD ($)	Nov. 09, 2016 USD ($)	Jun. 30, 2017 USD ($) $ / shares	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) item $ / shares	Jun. 30, 2016 USD ($)	Jan. 27, 2014 USD ($)
Loss Contingencies [Line Items]
Business Combination Contingent Consideration Arrangements, Contingent Value Right, Amount Per Share | $ / shares			$ 1.00		$ 1.00
Deductible related to litigation and contingent value right					$ 18.0
Contingent value right, percentage multiplier					90.00%
Number of contingent value rights outstanding | item					264,544,053
Amount which CVR holders are no longer entitled to payment			$ 312.0		$ 312.0
Contingent value right, period payable after final resolution					60 days
Business Combination, Contingent Consideration, Liability, Noncurrent			260.0		$ 260.0		$ 284.0
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability					8.0
Business Combination, Contingent Consideration, Liability, Current			0.0		0.0
Pending Litigation [Member] | Legal Matters Where Negative Outcome is Known or Probable [Member]
Loss Contingencies [Line Items]
Legal Fees			$ 1.0	$ 1.0	$ 1.0	$ 2.0
U.S. ex re. Baker vs. Community Health Systems, Inc. [Member]
Loss Contingencies [Line Items]
Judgment awarded		$ 1.9
Class Action Shareholder Federal Securities Cases [Member] | Pending Litigation [Member] | Litigation Matters For Which An Outcome Cannot Be Assessed [Member]
Loss Contingencies [Line Items]
Number of legal cases filed | item					3
Shareholder Derivative Actions [Member]
Loss Contingencies [Line Items]
Proceeds from legal settlement	$ 40.0
Shareholder Derivative Actions [Member] | Pending Litigation [Member] | Litigation Matters For Which An Outcome Cannot Be Assessed [Member]
Loss Contingencies [Line Items]
Number of legal cases filed | item					3