Consolidated Statements of (Loss) Income - 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
Consolidated Statements of (Loss) Income [Abstract]
Operating revenues (net of contractual allowances and discounts)									$ 18,398	$ 21,275	$ 22,564
Provision for bad debts									3,045	2,837	3,127
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
Operating costs and expenses:
Salaries and benefits									7,376	8,624	8,991
Supplies									2,672	3,011	3,048
Other operating expenses									3,864	4,248	4,520
Government and other legal settlements and related costs									(31)	16	4
Electronic health records incentive reimbursement									(28)	(70)	(160)
Rent									394	450	457
Depreciation and amortization									861	1,100	1,172
Impairment and (gain) loss on sale of businesses, net									2,123	1,919	68
Total operating costs and expenses									17,231	19,298	18,100
(Loss) income from operations									(1,878)	(860)	1,337
Interest expense, net of interest income of $11, $14 and $15 in 2017, 2016 and 2015, respectively									931	962	973
Loss from early extinguishment of debt									40	30	16
Gain on sale of investments in unconsolidated affiliates										(94)
Equity in earnings of unconsolidated affiliates									(16)	(43)	(63)
Loss from continuing operations before income taxes	(2,379)	(147)	(131)	(176)	(152)	(83)	(1,543)	63	(2,833)	(1,715)	411
(Benefit from) provision for income taxes									(449)	(104)	116
(Loss) income from continuing operations	(2,004)	(88)	(116)	(176)	(189)	(54)	(1,405)	37	(2,384)	(1,611)	295
Discontinued operations, net of taxes:
Loss from operations of entities sold or held for sale									(6)	(7)	(27)
Impairment of hospitals sold or held for sale									(6)	(8)	(5)
Loss on sale, net											(4)
Loss from discontinued operations, net of taxes	(3)	(2)	(6)	(1)	(9)	(2)	(1)	(1)	(12)	(15)	(36)
Net (loss) income									(2,396)	(1,626)	259
Less: Net income attributable to noncontrolling interests									63	95	101
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
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