Significant Payors (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Concentration Risk [Line Items]
Net service revenues	$ 864,499	$ 764,775	$ 648,791
Operating income	65,936	$ 44,507	$ 34,752
New York [Member] | CDPAP
Concentration Risk [Line Items]
Net service revenues	42,000
Operating income	$ 3,000
Revenues [Member] | Geographic Concentration Risk [Member] | Illinois [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	38.20%	37.70%	38.20%
Revenues [Member] | Illinois Department On Aging [Member] | Geographic Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	21.40%	23.00%	25.30%
Accounts Receivable [Member] | Illinois Department On Aging [Member] | Geographic Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	16.10%	15.90%