Insurance and Contractholder Liabilities - Unpaid Claims and Claims Expenses - Cigna Healthcare - Variances in Incurred Costs Related to Prior Years' Unpaid Claims and Claims Expenses (Details) - Cigna Healthcare - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Abstract]
Favorable (unfavorable) variance, amount	$ 144	$ 276
Favorable (unfavorable) variance, percentage	0.50%	0.90%
Actual completion factors
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Abstract]
Favorable (unfavorable) variance, amount	$ 1	$ 99
Favorable (unfavorable) variance, percentage	0.00%	0.30%
Medical cost trend
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Abstract]
Favorable (unfavorable) variance, amount	$ 143	$ 177
Favorable (unfavorable) variance, percentage	0.50%	0.60%