General - Customers Exceeding Ten Percent of Consolidated Net Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Significant customers
Revenue from Contract with Customer, Including Assessed Tax	$ 1,161,649	$ 1,122,379
MCC Business | Discontinued Operations, Held-for-sale
Significant customers
Managed care and other revenue		$ 720,034
Maximum
Significant customers
Term of contracts with customers	3 years
Term of contract extensions or renewals	2 years