Other Contract Holder Funds - Schedule of Policyholder Account Balance and Liability for Unpaid Claims and Claims Adjustment Expense (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025	Dec. 31, 2024
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	$ 76,249	$ 67,663
Variable Annuity
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	5,962	6,351	$ 7,206
RILA
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	28,830	20,282	11,685
Fixed Annuity
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	9,157	9,494	9,615
Fixed Index Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	8,655	7,946	8,515
Payout Annuity
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	827	854	844
Closed Block Life
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	10,228	10,494	10,750
Closed Block Annuity
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	997	1,057	$ 1,149
Institutional Products
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	11,432	11,021
Other Product Lines
Liability for Future Policy Benefit, Activity [Line Items]
Total other contract holder funds	$ 161	$ 164