CONSOLIDATED BALANCE SHEETS (Parenthetical - equity) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
AIG shareholders' equity:
Common stock, par value (in dollars per share)	$ 2.5	$ 2.5
Common stock, shares authorized	5,000,000,000	5,000,000,000
Common stock, shares issued	1,906,671,492	1,906,671,492
Treasury stock, shares of common stock	1,007,626,835	911,335,651