Business Optimization Initiatives (Employee Termination Costs) (Details) - Employee Termination [Member] $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)
Business Optimization Initiatives [Line Items]
Liabilities for employee termination costs, beginning balance	$ 122
Payments	(39)
Releases	(2)
Liabilities for employee termination costs, ending balance	81
CarelonRx Segment [Member]
Business Optimization Initiatives [Line Items]
Liabilities for employee termination costs, beginning balance	1
Payments	0
Releases	0
Liabilities for employee termination costs, ending balance	1
Other Segment [Member]
Business Optimization Initiatives [Line Items]
Liabilities for employee termination costs, beginning balance	3
Payments	(1)
Releases	(2)
Liabilities for employee termination costs, ending balance	0
Government Business [Member]
Business Optimization Initiatives [Line Items]
Liabilities for employee termination costs, beginning balance	57
Payments	(18)
Releases	0
Liabilities for employee termination costs, ending balance	39
Commercial and Specialty Business [Member]
Business Optimization Initiatives [Line Items]
Liabilities for employee termination costs, beginning balance	61
Payments	(20)
Releases	0
Liabilities for employee termination costs, ending balance	$ 41