v3.26.3
Earnings Per Share (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Basic Earnings Per Share (EPS):        
Net income (loss) attributable to AGL $ 78 $ 105 $ 205 $ 384
Less: Distributed and undistributed income (loss) available to nonvested shareholders 0 1 1 2
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic $ 78 $ 104 $ 204 $ 382
Basic shares (in shares) 44.0 47.4 44.4 48.8
Basic EPS (in dollars per share) $ 1.76 $ 2.20 $ 4.59 $ 7.82
Diluted EPS:        
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic $ 78 $ 104 $ 204 $ 382
Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries 0 0 0 0
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, diluted $ 78 $ 104 $ 204 $ 382
Basic shares (in shares) 44.0 47.4 44.4 48.8
Dilutive securities:        
Restricted stock awards (in shares) 0.3 0.6 0.4 0.6
Diluted shares (in shares) 44.3 48.0 44.8 49.4
Diluted EPS (in dollars per share) $ 1.75 $ 2.18 $ 4.55 $ 7.73
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect (in shares) 0.1 0.0 0.1 0.1