Revenue Recognition and Receivables - Adjustments to Operating Results (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	$ 563,462	$ 574,794	$ 426,063
Operating Expenses	450,686	458,122	342,932
Total Expenses	565,122	567,907	$ 425,323
Accounts receivable, net	66,257	64,929
Accumulated Deficit	(23,016)	$ (14,534)
Difference Between Revenue Guidance In Effect before And After Topic 606, Adjustment For Implicit Price Concession Of Bad Debt Expense | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	14,682
Difference Between Revenue Guidance In Effect before And After Topic 606, Adjustment For Implementation | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	(487)
Accounts receivable, net	(487)
Accumulated Deficit	487
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	14,195
Operating Expenses	14,682
Total Expenses	14,682
Accounts receivable, net	16,774
Accumulated Deficit	441
Difference Between Revenue Guidance In Effect before And After Topic 606, Allowance For Doubtful Accounts | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	17,261
Difference Between Revenue Guidance In Effect before And After Topic 606, Tax Adjustment | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accumulated Deficit	(46)
Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Patient Revenues, net	577,657
Operating Expenses	465,368
Total Expenses	579,804
Accounts receivable, net	83,031
Accumulated Deficit	(22,575)
Calculated under Revenue Guidance in Effect before Topic 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 66,257