Revenues - Schedule of Revenue by Payor Type (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 12,910,564	$ 10,072,214	$ 7,691,016
Commercial Insurance
Disaggregation of Revenue [Line Items]
Revenues	3,303,300	2,528,100	1,810,200
Medicaid
Disaggregation of Revenue [Line Items]
Revenues	1,495,200	1,166,500	979,100
Medicare Part A
Disaggregation of Revenue [Line Items]
Revenues	1,094,300	999,600	958,600
Medicare Part B
Disaggregation of Revenue [Line Items]
Revenues	82,800	95,900	82,800
Medicare Part C
Disaggregation of Revenue [Line Items]
Revenues	2,413,100	1,665,000	1,450,400
Medicare Part D
Disaggregation of Revenue [Line Items]
Revenues	4,097,800	3,202,000	2,031,900
Private and Other
Disaggregation of Revenue [Line Items]
Revenues	424,100	415,100	378,000
Pharmacy Solutions
Disaggregation of Revenue [Line Items]
Revenues	11,445,800	8,754,300	6,522,500
Pharmacy Solutions \| Commercial Insurance
Disaggregation of Revenue [Line Items]
Revenues	3,114,600	2,360,000	1,657,700
Pharmacy Solutions \| Medicaid
Disaggregation of Revenue [Line Items]
Revenues	1,093,200	829,100	656,100
Pharmacy Solutions \| Medicare Part A
Disaggregation of Revenue [Line Items]
Revenues	572,800	546,400	549,300
Pharmacy Solutions \| Medicare Part B
Disaggregation of Revenue [Line Items]
Revenues	76,400	70,300	61,200
Pharmacy Solutions \| Medicare Part C
Disaggregation of Revenue [Line Items]
Revenues	2,277,500	1,547,100	1,384,300
Pharmacy Solutions \| Medicare Part D
Disaggregation of Revenue [Line Items]
Revenues	4,097,800	3,202,000	2,031,900
Pharmacy Solutions \| Private and Other
Disaggregation of Revenue [Line Items]
Revenues	213,500	199,400	182,000
Provider Services
Disaggregation of Revenue [Line Items]
Revenues	1,464,800	1,317,900	1,168,500
Provider Services \| Commercial Insurance
Disaggregation of Revenue [Line Items]
Revenues	188,700	168,100	152,500
Provider Services \| Medicaid
Disaggregation of Revenue [Line Items]
Revenues	402,000	337,400	323,000
Provider Services \| Medicare Part A
Disaggregation of Revenue [Line Items]
Revenues	521,500	453,200	409,300
Provider Services \| Medicare Part B
Disaggregation of Revenue [Line Items]
Revenues	6,400	25,600	21,600
Provider Services \| Medicare Part C
Disaggregation of Revenue [Line Items]
Revenues	135,600	117,900	66,100
Provider Services \| Private and Other
Disaggregation of Revenue [Line Items]
Revenues	$ 210,600	$ 215,700	$ 196,000
Product Concentration Risk \| Revenue
Disaggregation of Revenue [Line Items]
% of Revenue	100.00%	100.00%	100.00%
Product Concentration Risk \| Revenue \| Commercial Insurance
Disaggregation of Revenue [Line Items]
% of Revenue	25.60%	25.10%	23.60%
Product Concentration Risk \| Revenue \| Medicaid
Disaggregation of Revenue [Line Items]
% of Revenue	11.60%	11.50%	12.70%
Product Concentration Risk \| Revenue \| Medicare Part A
Disaggregation of Revenue [Line Items]
% of Revenue	8.40%	9.90%	12.40%
Product Concentration Risk \| Revenue \| Medicare Part B
Disaggregation of Revenue [Line Items]
% of Revenue	0.60%	1.00%	1.10%
Product Concentration Risk \| Revenue \| Medicare Part C
Disaggregation of Revenue [Line Items]
% of Revenue	18.70%	16.60%	18.90%
Product Concentration Risk \| Revenue \| Medicare Part D
Disaggregation of Revenue [Line Items]
% of Revenue	31.70%	31.80%	26.40%
Product Concentration Risk \| Revenue \| Private and Other
Disaggregation of Revenue [Line Items]
% of Revenue	3.40%	4.10%	4.90%
Product Concentration Risk \| Revenue \| Pharmacy Solutions
Disaggregation of Revenue [Line Items]
% of Revenue	88.70%	86.90%	84.80%
Product Concentration Risk \| Revenue \| Pharmacy Solutions \| Commercial Insurance
Disaggregation of Revenue [Line Items]
% of Revenue	24.10%	23.40%	21.60%
Product Concentration Risk \| Revenue \| Pharmacy Solutions \| Medicaid
Disaggregation of Revenue [Line Items]
% of Revenue	8.50%	8.20%	8.50%
Product Concentration Risk \| Revenue \| Pharmacy Solutions \| Medicare Part A
Disaggregation of Revenue [Line Items]
% of Revenue	4.40%	5.40%	7.10%
Product Concentration Risk \| Revenue \| Pharmacy Solutions \| Medicare Part B
Disaggregation of Revenue [Line Items]
% of Revenue	0.60%	0.70%	0.80%
Product Concentration Risk \| Revenue \| Pharmacy Solutions \| Medicare Part C
Disaggregation of Revenue [Line Items]
% of Revenue	17.60%	15.40%	18.00%
Product Concentration Risk \| Revenue \| Pharmacy Solutions \| Medicare Part D
Disaggregation of Revenue [Line Items]
% of Revenue	31.70%	31.80%	26.40%
Product Concentration Risk \| Revenue \| Pharmacy Solutions \| Private and Other
Disaggregation of Revenue [Line Items]
% of Revenue	1.80%	2.00%	2.40%
Product Concentration Risk \| Revenue \| Provider Services
Disaggregation of Revenue [Line Items]
% of Revenue	11.30%	13.10%	15.20%
Product Concentration Risk \| Revenue \| Provider Services \| Commercial Insurance
Disaggregation of Revenue [Line Items]
% of Revenue	1.50%	1.70%	2.00%
Product Concentration Risk \| Revenue \| Provider Services \| Medicaid
Disaggregation of Revenue [Line Items]
% of Revenue	3.10%	3.30%	4.20%
Product Concentration Risk \| Revenue \| Provider Services \| Medicare Part A
Disaggregation of Revenue [Line Items]
% of Revenue	4.00%	4.50%	5.30%
Product Concentration Risk \| Revenue \| Provider Services \| Medicare Part B
Disaggregation of Revenue [Line Items]
% of Revenue	0.00%	0.30%	0.30%
Product Concentration Risk \| Revenue \| Provider Services \| Medicare Part C
Disaggregation of Revenue [Line Items]
% of Revenue	1.10%	1.20%	0.90%
Product Concentration Risk \| Revenue \| Provider Services \| Private and Other
Disaggregation of Revenue [Line Items]
% of Revenue	1.60%	2.10%	2.50%