Significant Accounting Policies - Narrative (Details) store in Thousands, clinic in Thousands, people in Millions, patient in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2025 USD ($) clinic people patient store segment	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($) program
Significant Accounting Policies [Line Items]
Number of pharmacy plan members | people	88
Number of patients served per year (more than) | patient	0.8
Number of reportable segments | segment	4
Allowance for credit losses	$ 392		$ 407
Total premium deficiency reserve	448	$ 0
Premium deficiency reserve, charge of unamortized acquisition costs	17
Premium deficiency reserve, charge to health care costs	431
Loss on Accountable Care assets	247
Pre-tax loss on divestiture	$ (236)	$ 0
Pharmacy & Consumer Wellness
Significant Accounting Policies [Line Items]
Number of retail locations (more than) | store	9
Health Services
Significant Accounting Policies [Line Items]
Number of walk in medical clinics (more than) | clinic	1
Number of programs administered | program			2
Loss on Accountable Care assets	$ 247
Loss on termination of program	11
Health Services | Disposal Group, Disposed of by Sale, Not Discontinued Operations | MSSP
Significant Accounting Policies [Line Items]
Pre-tax loss on divestiture	(236)
Intangible assets and goodwill removed due to divestiture	$ 342
Health Care Benefits
Significant Accounting Policies [Line Items]
Number of people served (more than) | people	37