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, 2025	Mar. 31, 2024
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Abstract]
Favorable (unfavorable) variance, amount	$ 222	$ 226
Favorable (unfavorable) variance, percentage	0.60%	0.60%
Actual completion factors and other
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Abstract]
Favorable (unfavorable) variance, amount	$ 96	$ 76
Favorable (unfavorable) variance, percentage	0.30%	0.20%
Medical cost trend
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Abstract]
Favorable (unfavorable) variance, amount	$ 126	$ 150
Favorable (unfavorable) variance, percentage	0.30%	0.40%