Commitments And Contingencies (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Commitments And Contingencies [Line Items]
Gross premium tax rate, state of California	2.35%
Long-term purchase commitment, amount	$ 697
Minimum [Member]
Commitments And Contingencies [Line Items]
Aggregate settlement amount	0
Maximum [Member]
Commitments And Contingencies [Line Items]
Aggregate settlement amount	250
Anthem, Inc. v. Express Scripts, Inc. [Member]
Commitments And Contingencies [Line Items]
Proceeds originally received at time of divestiture	4,675
Anthem, Inc. v. Express Scripts, Inc. [Member] | Damages for Pharmacy Pricing [Member]
Commitments And Contingencies [Line Items]
Approximate amount of damages sought for breaches	14,800
Anthem, Inc. v. Express Scripts, Inc. [Member] | Damages for Operational Breaches [Member]
Commitments And Contingencies [Line Items]
Approximate amount of damages sought for breaches	158
BCBS Antitrust Litigation [Member]
Commitments And Contingencies [Line Items]
Aggregate settlement amount	596
Loss Contingency Accrual, Payments	$ 506