Significant Accounting Policies - Narrative (Details) store in Thousands, clinic in Thousands, people in Millions, patient in Millions, $ in Millions		1 Months Ended		3 Months Ended		9 Months Ended
	Jan. 01, 2023 USD ($)	Jan. 31, 2024 state	Jan. 31, 2023 state	Sep. 30, 2023 USD ($) clinic people patient store primaryCareMedicalClinic	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) clinic people patient store Segment state primaryCareMedicalClinic	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Significant Accounting Policies [Line Items]
Number of pharmacy plan members | people				110		110
Number of patients served per year (more than) | patient				1		1
Number of reportable segments | Segment						4
Goodwill impairment	$ 0
Client Health Information Network Services, Fees Expensed
Significant Accounting Policies [Line Items]
Transactions with related party				$ 12	$ 16	$ 44	$ 47
Pharmaceutical Inventory Purchases, Payments Received
Significant Accounting Policies [Line Items]
Transactions with related party				5	$ 22	34	$ 66
Other Insurance Liabilities
Significant Accounting Policies [Line Items]
Liability for future policy benefits				366		366		$ 334
Other Long-Term Insurance Liabilities
Significant Accounting Policies [Line Items]
Liability for future policy benefits				$ 4,400		$ 4,400		$ 4,700
Pharmacy & Consumer Wellness
Significant Accounting Policies [Line Items]
Number of retail locations (more than) | store				9		9
Health Services
Significant Accounting Policies [Line Items]
Number of walk in medical clinics (more than) | clinic				1		1
Number of primary care medical clinics | primaryCareMedicalClinic				192		192
Health Care Benefits
Significant Accounting Policies [Line Items]
Number of people served (more than) | people				35		35
Number of states in which the Company has entered the individual public health insurance exchange | state						8
Additional number of states in which the Company entered the individual public health insurance exchange | state			4
Health Care Benefits | Forecast
Significant Accounting Policies [Line Items]
Additional number of states in which the Company entered the individual public health insurance exchange | state		5