Policyholder Account Balances - Schedule of Policyholder Account Balances (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Dec. 31, 2023
Policyholder Account Balance [Line Items]
Policyholder account balances	$ 133,223	$ 126,197
Variable Annuities
Policyholder Account Balance [Line Items]
Policyholder account balances	39,165	35,267	$ 34,344	$ 29,141
Fixed Annuities
Policyholder Account Balance [Line Items]
Policyholder account balances	27,874	25,963	26,359	25,355
UL and Other
Policyholder Account Balance [Line Items]
Policyholder account balances	36,008	36,599	36,692	37,180
Retirement Plan Services
Policyholder Account Balance [Line Items]
Policyholder account balances	23,852	23,619	$ 23,727	$ 23,784
Other
Policyholder Account Balance [Line Items]
Policyholder account balances	6,324	4,749
Other | FABN | Sustainable Financing | The Lincoln National Life Insurance Company
Policyholder Account Balance [Line Items]
Policyholder account balances	1,900	0
Other | Reinsurance Agreement
Policyholder Account Balance [Line Items]
Policyholder account balances	$ 4,100	$ 4,400