Quarterly Financial Data (Schedule of Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Data [Abstract]
Net operating revenues	$ 3,059	$ 3,666	$ 4,144	$ 4,486	$ 4,469	$ 4,380	$ 4,590	$ 4,999	$ 15,353	$ 18,438	$ 19,437
Income (loss) from continuing operations before income taxes	(2,379)	(147)	(131)	(176)	(152)	(83)	(1,543)	63	(2,833)	(1,715)	411
Income (loss) from continuing operations, net of taxes	(2,004)	(88)	(116)	(176)	(189)	(54)	(1,405)	37	(2,384)	(1,611)	295
Loss from discontinued operations, net of taxes	(3)	(2)	(6)	(1)	(9)	(2)	(1)	(1)	(12)	(15)	(36)
Net income (loss) attributable to Community Health Systems, Inc. stockholders	$ (2,013)	$ (110)	$ (137)	$ (199)	$ (220)	$ (79)	$ (1,432)	$ 11	$ (2,459)	$ (1,721)	$ 158
Basic (loss) income per share attributable to Community Health Systems, Inc. common stockholders:
Continuing operations	$ (17.95)	$ (0.96)	$ (1.17)	$ (1.78)	$ (1.91)	$ (0.69)	$ (12.90)	$ 0.11	$ (21.89)	$ (15.41)	$ 1.69
Discontinued operations	(0.03)	(0.02)	(0.06)	(0.01)	(0.09)	(0.02)	(0.01)	(0.01)	(0.11)	(0.13)	(0.31)
Net (loss) income	(17.98)	(0.98)	(1.22)	(1.79)	(1.99)	(0.71)	(12.91)	0.10	(22.00)	(15.54)	1.38
Diluted (loss) income per share attributable to Community Health Systems, Inc. common stockholders:
Continuing operations	(17.95)	(0.96)	(1.17)	(1.78)	(1.91)	(0.69)	(12.90)	0.11	(21.89)	(15.41)	1.68
Discontinued operations	(0.03)	(0.02)	(0.06)	(0.01)	(0.09)	(0.02)	(0.01)	(0.01)	(0.11)	(0.13)	(0.31)
Net (loss) income	$ (17.98)	$ (0.98)	$ (1.22)	$ (1.79)	$ (1.99)	$ (0.71)	$ (12.91)	$ 0.10	$ (22.00)	$ (15.54)	$ 1.37
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
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