v3.26.1
Earnings Per Share (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Basic Earnings Per Share (EPS):        
Net income (loss) attributable to AGL $ 39 $ 103 $ 127 $ 279
Less: Distributed and undistributed income (loss) available to nonvested shareholders 0 0 1 2
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic $ 39 $ 103 $ 126 $ 277
Basic shares (in shares) 44.3 48.9 44.6 49.5
Basic EPS (in dollars per share) $ 0.88 $ 2.10 $ 2.82 $ 5.60
Diluted EPS:        
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic $ 39 $ 103 $ 126 $ 277
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 $ 39 $ 103 $ 126 $ 277
Basic shares (in shares) 44.3 48.9 44.6 49.5
Dilutive securities:        
Restricted stock awards (in shares) 0.3 0.5 0.4 0.6
Diluted shares (in shares) 44.6 49.4 45.0 50.1
Diluted EPS (in dollars per share) $ 0.88 $ 2.08 $ 2.80 $ 5.54
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect (in shares) 0.1 0.2 0.2 0.1