Shares and Stockholders' Equity - Reconciliation of the Denominator Calculations of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Stockholders' Equity Note [Abstract]
Net income (loss) available to common stockholders – basic	$ 688	$ 884	$ (69)	$ 2,070
Deferred units of LNC stock in our deferred compensation plans	0	0	0	3
Net income (loss) available to common stockholders	$ 688	$ 884	$ (69)	$ 2,073
Weighted-average shares, as used in basic calculation (in shares)	177,175,326	170,620,161	174,264,554	170,335,077
Incremental common shares from assumed exercise or issuance of stock-based incentive compensation awards (in shares)	2,773,060	1,553,402	2,769,320	1,324,837
Average deferred compensation shares (in shares)	654,279	719,003	0	703,742
Weighted-average shares, as used in diluted calculation (in shares)	180,602,665	172,892,566	177,033,874	172,363,656
Net income (loss) per share:
Basic (in dollars per share)	$ 3.88	$ 5.18	$ (0.39)	$ 12.16
Diluted (in dollars per share)	$ 3.80	$ 5.11	$ (0.39)	$ 12.03