Basis of Presentation and Significant Accounting Policies (Narrative) (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) Hospital	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2014 Hospital	Apr. 29, 2016 shares
Basis Of Presentation And Significant Accounting Policies [Line Items]
Operating revenues, net of contractual allowances and discounts	$ 587,945,000	$ 614,484,000
Reclassification from managed care and commercial revenues to Medicare revenues		41,700,000
Increase (decrease) in net operating revenues during period for contractual allowance adjustments related to final cost report settlements on previous program reimbursements	(1,400,000)	(1,800,000)
Operating revenues	3,068,323,000	3,080,653,000
Provider taxes and other expenses	526,614,000	528,460,000
Accounts receivable, net of contractual allowances	396,030,000		$ 380,685,000
General and administrative costs	15,700,000	12,000,000
Acquired finite-lived intangible asset, residual value	$ 0
New date of annual goodwill impairment test	The Company performs its annual testing of impairment for goodwill in the fourth quarter of each year.
Noncontrolling interests and redeemable noncontrolling interests	The Company’s consolidated and combined financial statements include all assets, liabilities, revenues and expenses of less than 100% owned entities that it controls.
Maximum period during which assets held for sale sold	12 months
Spin-off from CHS [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of shares distributed to each stockholder in spin-off | shares					1
Number of shares held by each stockholder of the parent used to determine share distribution in spin-off | shares					4
Restricted Stock [Member] | Spin-off from CHS [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of shares distributed to each stockholder in spin-off | shares					1
Number of shares held by each stockholder of the parent used to determine share distribution in spin-off | shares					4
Accrued Salaries and Benefits [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Undiscounted reserve for self-insured employee health benefits	$ 8,800,000		$ 11,000,000
Capitalized Internal Use Software, Except Significant System Conversions [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Finite-lived intangible assets, useful life	3 years
Community Health Systems, Inc [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of Hospitals | Hospital				4
Illinois [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of Hospitals | Hospital	9
Accounts Receivable [Member] | Credit Concentration Risk [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Concentration risk, percentage	100.00%		100.00%
Sales Revenue, Net [Member] | Credit Concentration Risk [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Concentration risk, percentage	5.00%		5.00%
Medicare Revenues [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Operating revenues, net of contractual allowances and discounts	$ 48,300,000	41,700,000
California Hospital Quality Assurance Fee [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Operating revenues	0	11,000,000
Provider taxes and other expenses	0	2,700,000
Charity Care [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Operating revenues	12,500,000	7,800,000
Medicare [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Operating revenues, net of contractual allowances and discounts	175,293,000	175,534,000
Accounts receivable, net of contractual allowances	$ 72,800,000		$ 72,600,000
Medicare [Member] | Accounts Receivable [Member] | Credit Concentration Risk [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Concentration risk, percentage	9.70%		9.80%
Medicaid [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Operating revenues, net of contractual allowances and discounts	$ 96,669,000	$ 103,068,000
Medicaid [Member] | Illinois [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Accounts receivable, net of contractual allowances	$ 38,500,000		$ 34,800,000
Medicaid [Member] | Accounts Receivable [Member] | Credit Concentration Risk [Member] | Illinois [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Concentration risk, percentage	5.10%		4.70%
Maximum [Member] | Capitalized Internal Use Software, Significant System Conversions [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Finite-lived intangible assets, useful life	10 years
Maximum [Member] | Land Improvements [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated useful life of asset	20 years
Maximum [Member] | Buildings and Improvements [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated useful life of asset	40 years
Maximum [Member] | Equipment and Fixtures [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated useful life of asset	18 years
Minimum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of days from date of discharge in which company establishes doubtful accounts reserve on non-self pay payor receivables	365 days
Minimum [Member] | Capitalized Internal Use Software, Significant System Conversions [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Finite-lived intangible assets, useful life	8 years
Minimum [Member] | Land Improvements [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated useful life of asset	3 years
Minimum [Member] | Buildings and Improvements [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated useful life of asset	5 years
Minimum [Member] | Equipment and Fixtures [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated useful life of asset	3 years
Senior Credit Facility [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Secured net leverage ratio	383.00%		393.00%
Senior Credit Facility [Member] | Period from July 1, 2017 to December 31, 2018 [Member] | Maximum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Secured net leverage ratio	475.00%
Senior Credit Facility [Member] | Period from July 1, 2017 to June 30, 2018 [Member] | Maximum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Secured net leverage ratio	425.00%
Senior Credit Facility [Member] | Period from January 1, 2019 and thereafter [Member] | Maximum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Secured net leverage ratio	400.00%