Other Comprehensive Income (Schedule of Amounts Reclassified Out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net									$ 931	$ 962	$ 973
Loss from continuing operations before income taxes	$ (2,379)	$ (147)	$ (131)	$ (176)	$ (152)	$ (83)	$ (1,543)	$ 63	(2,833)	(1,715)	411
Tax benefit									449	104	(116)
Net (loss) income attributable to Community Health Systems, Inc. stockholders	$ (2,013)	$ (110)	$ (137)	$ (199)	$ (220)	$ (79)	$ (1,432)	$ 11	(2,459)	(1,721)	$ 158
Reclassification, net of tax									(28)	(23)
Change in Fair Value of Interest Rate Swaps [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification, net of tax									(19)	(34)
Change in Fair Value of Interest Rate Swaps [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net									(30)	(54)
Tax benefit									11	20
Net (loss) income attributable to Community Health Systems, Inc. stockholders									(19)	(34)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification, Total before tax									(2)	(2)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification, Total before tax									(1)	1
Accumulated Defined Benefit Plans Adjustment, Net Transition Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification, Total before tax									(13)
Change in Unrecognized Pension Cost Components [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification, Total before tax									(16)	(3)
Tax benefit									7	1
Reclassification, net of tax									$ (9)	$ (2)