Business Combinations (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended
	Nov. 13, 2018	Jul. 06, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Oct. 15, 2018
Business Combinations [Line Items]
Revenues			$ 651,100	$ 601,273	$ 1,239,380	$ 1,124,932
Income before income taxes			146,273	141,765	285,155	250,250
Income from operations			157,078	146,016	301,211	258,574
Acquisition related expenses			6,123		6,123
Income tax expense (benefit)			21,634	132,238	54,778	154,599
MatrixCare [Member]
Business Combinations [Line Items]
Revenues			15,400		15,400
Income before income taxes			1,000		1,000
Other Acquisitions [Member]
Business Combinations [Line Items]
Assets acquired			192,328		192,328
Acquisition related expenses					6,100
MatrixCare [Member]
Business Combinations [Line Items]
Percentage of acquisition shares	100.00%
Total purchase price of acquisition	$ 750,000
Assets acquired			865,476		865,476
Deferred revenue, fair value adjustment			2,000		2,000
Amortization of intangible assets					3,000
MatrixCare [Member] | Excluding Impact Of Fair Value Purchase Price Adjustment To Deferred Revenue [Member]
Business Combinations [Line Items]
Revenues					17,400
Income from operations					4,000
MatrixCare [Member] | Pro Forma [Member]
Business Combinations [Line Items]
Amortization of intangible assets			1,700	3,600	1,300	7,500
Net interest expense associated with debt issued			500	3,200	2,600	6,600
Acquisition related expenses			3,700		16,700
Income tax expense (benefit)			$ 0	$ 9,800	$ 1,400	$ 7,400
Healthcarefirst [Member]
Business Combinations [Line Items]
Date of acquisition agreement					Jul. 06, 2018
Percentage of acquisition shares		100.00%
Total purchase price of acquisition		$ 126,300
HB Healthcare [Member]
Business Combinations [Line Items]
Percentage of acquisition shares							100.00%