Fair Value of Financial Instruments - Changes in Unrealized Gains (Losses) Within Level 3 Financial Instruments Carried at Fair Value and Still Held (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Trading securities
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in unrealized gains (losses) included in net income	$ 2	$ 0	$ 8
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Realized gain (loss)
Equity securities
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in unrealized gains (losses) included in net income	(5)	(1)	$ (16)
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Realized gain (loss)
Mortgage loans on real estate
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in unrealized gains (losses) included in net income	(3)	0	$ (8)
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Realized gain (loss)
Derivative investments
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in unrealized gains (losses) included in net income	(35)	(121)	$ 1
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Realized gain (loss)
MRBs
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in unrealized gains (losses) included in net income	197	904	$ 1,071
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Realized gain (loss)
Other assets – LPR ceded derivative
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in unrealized gains (losses) included in net income	13	(16)	$ (6)
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Realized gain (loss)
Funds withheld reinsurance liabilities – reinsurance-related embedded derivatives
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in unrealized gains (losses) included in net income	(97)	(59)	$ 0
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Realized gain (loss)
Indexed annuity ceded embedded derivatives
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in unrealized gains (losses) included in net income	$ 915	$ 1,061	$ (20)
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Realized gain (loss)

LINCOLN NATIONAL LIFE INSURANCE CO /IN/ 10-K