General - Customers Exceeding Ten Percent of Segment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Significant customers
Revenues	$ 1,254,118	$ 1,170,117	$ 3,636,535	$ 3,392,571
Healthcare
Significant customers
Revenues	580,278	489,451	1,698,427	1,459,378
Healthcare | Customer A
Significant customers
Revenues			283,373	259,286
Healthcare | Customer B
Significant customers
Revenues			300,450	147,177
Pharmacy Management
Significant customers
Revenues	$ 677,339	$ 685,928	1,948,919	1,948,203
Pharmacy Management | Customer C
Significant customers
Revenues			$ 247,786	$ 284,697