v3.24.0.1
Summary of Significant Accounting Policies - Adjusted Income Statement and Comprehensive Income to Apply Adopted Guidance (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Income Statement [Abstract]      
Premiums $ 33,254 $ 31,856 $ 31,285
Policy fees 2,797 2,913 3,005
Total net realized gains (losses) (4,608) 7,064 2,271
Total revenues 46,802 54,450 52,157
Policyholder benefits and losses incurred 24,755 22,176 23,785
Change in the fair value of market risk benefits, net 2 (958) (447)
Interest credited to policyholder account balances 4,424 3,744 3,570
Amortization of deferred policy acquisition costs 4,808 4,557 4,524
General operating and other expenses 8,499 9,122 8,728
Total benefits, losses and expenses 42,944 40,151 38,810
Income from continuing operations before income tax expense (benefit) 3,858 14,299 13,347
Income tax expense (benefit) (20) 3,025 2,441
Income from continuing operations 3,878 11,274 10,906
Net income 3,878 11,273 10,906
Net income from continuing operations attributable to noncontrolling interests 235 1,046 539
Net income attributable to AIG 3,643 10,227 10,367
Net income (loss) attributable to AIG common shareholders $ 3,614 $ 10,198 $ 10,338
Income (loss) attributable to AIG common shareholders (in dollars per share) $ 5.02 $ 13.10 $ 12.10
Net income attributable to AIG common shareholders (in dollars per share) $ 4.98 $ 12.94 $ 11.95
Statement of Comprehensive Income [Abstract]      
Net income $ 3,878 $ 11,273 $ 10,906
Change in unrealized appreciation (depreciation) of fixed maturity securities on which allowance for credit losses was taken 14 (94) 44
Change in unrealized appreciation (depreciation) of all other investments 7,134 (38,408) (7,151)
Change in fair value of market risk benefits attributable to changes in our own credit risk (544) 1,294 179
Change in the discount rates used to measure traditional and limited payment long-duration insurance contracts (871) 5,544 1,361
Change in foreign currency translation adjustments 102 (613) (180)
Other comprehensive income (loss) 5,940 (32,303) (5,424)
Comprehensive income (loss) 9,818 (21,030) 5,482
Comprehensive income (loss) attributable to noncontrolling interests 1,534 (1,454) 440
Comprehensive income (loss) attributable to AIG $ 8,284 (19,576) 5,042
As Previously Reported      
Income Statement [Abstract]      
Premiums   31,857 31,259
Policy fees   2,972 3,051
Total net realized gains (losses)   8,991 2,151
Total revenues   56,437 52,057
Policyholder benefits and losses incurred   22,771 24,388
Change in the fair value of market risk benefits, net   0 0
Interest credited to policyholder account balances   3,709 3,557
Amortization of deferred policy acquisition costs   4,970 4,573
General operating and other expenses   9,195 8,790
Total benefits, losses and expenses   42,155 39,958
Income from continuing operations before income tax expense (benefit)   14,282 12,099
Income tax expense (benefit)   3,006 2,176
Income from continuing operations   11,276 9,923
Net income   11,275 9,923
Net income from continuing operations attributable to noncontrolling interests   999 535
Net income attributable to AIG   10,276 9,388
Net income (loss) attributable to AIG common shareholders   $ 10,247 $ 9,359
Income (loss) attributable to AIG common shareholders (in dollars per share)   $ 13.16 $ 10.95
Net income attributable to AIG common shareholders (in dollars per share)   $ 13.01 $ 10.82
Statement of Comprehensive Income [Abstract]      
Net income   $ 11,275 $ 9,923
Change in unrealized appreciation (depreciation) of fixed maturity securities on which allowance for credit losses was taken   (87) 35
Change in unrealized appreciation (depreciation) of all other investments   (32,775) (6,001)
Change in fair value of market risk benefits attributable to changes in our own credit risk   0 0
Change in the discount rates used to measure traditional and limited payment long-duration insurance contracts   0 0
Change in foreign currency translation adjustments   (514) (187)
Other comprehensive income (loss)   (33,402) (5,830)
Comprehensive income (loss)   (22,127) 4,093
Comprehensive income (loss) attributable to noncontrolling interests   (1,584) 430
Comprehensive income (loss) attributable to AIG   (20,543) 3,663
Effect of Change      
Income Statement [Abstract]      
Premiums   (1) 26
Policy fees   (59) (46)
Total net realized gains (losses)   (1,927) 120
Total revenues   (1,987) 100
Policyholder benefits and losses incurred   (595) (603)
Change in the fair value of market risk benefits, net   (958) (447)
Interest credited to policyholder account balances   35 13
Amortization of deferred policy acquisition costs   (413) (49)
General operating and other expenses   (73) (62)
Total benefits, losses and expenses   (2,004) (1,148)
Income from continuing operations before income tax expense (benefit)   17 1,248
Income tax expense (benefit)   19 265
Income from continuing operations   (2) 983
Net income   (2) 983
Net income from continuing operations attributable to noncontrolling interests   47 4
Net income attributable to AIG   (49) 979
Net income (loss) attributable to AIG common shareholders   $ (49) $ 979
Income (loss) attributable to AIG common shareholders (in dollars per share)   $ (0.06) $ 1.15
Net income attributable to AIG common shareholders (in dollars per share)   $ (0.07) $ 1.13
Statement of Comprehensive Income [Abstract]      
Net income   $ (2) $ 983
Change in unrealized appreciation (depreciation) of fixed maturity securities on which allowance for credit losses was taken   (7) 9
Change in unrealized appreciation (depreciation) of all other investments   (5,633) (1,150)
Change in fair value of market risk benefits attributable to changes in our own credit risk   1,294 179
Change in the discount rates used to measure traditional and limited payment long-duration insurance contracts   5,544 1,361
Change in foreign currency translation adjustments   (99) 7
Other comprehensive income (loss)   1,099 406
Comprehensive income (loss)   1,097 1,389
Comprehensive income (loss) attributable to noncontrolling interests   130 10
Comprehensive income (loss) attributable to AIG   $ 967 $ 1,379