Shares and Stockholders' Equity - Reconciliation of the Denominator Calculations of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Stockholders' Equity Note [Abstract]
Net income (loss) available to common stockholders – basic	$ 1,086	$ 3,184	$ (834)
Deferred units of LNC stock in our deferred compensation plans	0	3	(1)
Net income (loss) available to common stockholders	$ 1,086	$ 3,187	$ (835)
Weighted-average shares, as used in basic calculation (in shares)	182,674,725	170,597,104	169,562,903
Incremental common shares from assumed exercise or issuance of stock-based incentive compensation awards (in shares)	3,387,362	1,789,530	570,943
Average deferred compensation shares (in shares)	0	693,791	604,809
Weighted-average shares, as used in diluted calculation (in shares)	186,062,087	173,080,425	170,738,655
Net income (loss) per share:
Basic (in dollars per share)	$ 5.94	$ 18.66	$ (4.92)
Diluted (in dollars per share)	$ 5.83	$ 18.41	$ (4.92)