Stockholders' Deficit - Schedule of Impact of Noncontrolling Interest to Stockholders' Deficit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Net income (loss) attributable to Community Health Systems,Inc. stockholders	$ 511	$ (675)	$ (788)
Net increase (decrease) in Community Health Systems,Inc. paid-in-capital for purchase of subsidiary partnership interests	3	3	(4)
Net transfers to the noncontrolling interests	3	3	(4)
Change to Community Health Systems, Inc. stockholders' deficit from net income (loss) attributable to Community Health Systems, Inc. stockholders and transfers to noncontrolling interests	$ 514	$ (672)	$ (792)