Earnings Per Share (Schedule of Calculation of Numerator and Denominator in Earnings Per Share) (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
Numerator:
Loss from continuing operations, net of taxes	$ (2,004)	$ (88)	$ (116)	$ (176)	$ (189)	$ (54)	$ (1,405)	$ 37	$ (2,384)	$ (1,611)	$ 295
Less: Income from continuing operations attributable to noncontrolling interests, net of taxes									63	95	101
Loss from continuing operations attributable to Community Health Systems, Inc. common stockholders - basic and diluted									(2,447)	(1,706)	194
Loss from discontinued operations, net of taxes	$ (3)	$ (2)	$ (6)	$ (1)	$ (9)	$ (2)	$ (1)	$ (1)	(12)	(15)	(36)
Less: Loss from discontinued operations attributable to noncontrolling interests, net of taxes
Loss from discontinued operations attributable to Community Health Systems, Inc. common stockholders - basic and diluted									$ (12)	$ (15)	$ (36)
Denominator:
Weighted-average number of shares outstanding - basic	111,971,628	111,935,738	111,909,858	111,252,331	110,905,052	110,888,040	110,879,285	110,247,867	111,769,821	110,730,971	114,454,674
Effect of dilutive securities:
Restricted stock awards											449,961
Employee stock options											357,188
Other equity-based awards											10,581
Weighted-average number of shares outstanding - diluted	111,971,628	111,935,738	111,909,858	111,252,331	110,905,052	110,888,040	110,879,285	110,309,372	111,769,821	110,730,971	115,272,404