QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details - Consolidated Statements of Income (Loss)) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
Total revenues	$ 12,560	$ 11,486	$ 11,631	$ 11,712	$ 12,635	$ 11,751	$ 12,502	$ 12,632	$ 47,389	$ 49,520	$ 52,367
Income (loss) from continuing operations before income tax expense	(695)	(1,527)	1,252	1,227	875	(2,803)	1,667	1,727	257	1,466	(74)
Income (loss) from discontinued operations, net of income tax expense	(2)	(39)	0	(1)	(3)	(1)	8	0	(42)	4	(90)
Net income (loss)	(560)	(1,259)	931	949	(6,672)	(1,713)	1,118	1,211	61	(6,056)	(349)
Net income from continuing operations attributable to noncontrolling interests	62	0	(6)	11	(12)	26	(12)	26	67	28	500
Net income (loss) attributable to AIG	$ (622)	$ (1,259)	$ 937	$ 938	$ (6,660)	$ (1,739)	$ 1,130	$ 1,185	$ (6)	$ (6,084)	$ (849)
Basic:
Income (loss) from continuing operations	$ (0.7)	$ (1.37)	$ 1.04	$ 1.03	$ (7.33)	$ (1.91)	$ 1.21	$ 1.21	$ 0.04	$ (6.54)	$ (0.7)
Income (loss) from discontinued operations	(0.7)	(0.04)	0	0	0	0	0.01	0	(0.05)	0	(0.08)
Diluted:
Income (loss) from continuing operations	(0.7)	(1.37)	1.02	1.01	(7.33)	(1.91)	1.18	1.18	0.04	(6.54)	(0.7)
Loss from discontinued operations	$ (0.7)	$ (0.04)	$ 0	$ 0	$ 0	$ 0	$ 0.01	$ 0	$ (0.05)	$ 0	$ (0.08)
Weighted average shares outstanding:
Basic	887,508,718	895,237,359	903,215,488	907,951,597	908,115,499	908,667,044	925,751,084	980,777,243	898,405,537	930,561,286	1,091,085,131
Diluted	887,508,718	895,237,359	916,572,481	925,266,577	908,115,499	908,667,044	948,248,771	1,005,315,030	910,141,242	930,561,286	1,091,085,131
Noteworthy quarterly items income (expense):
Other-than-temporary impairments	$ 93	$ 35	$ 36	$ 87	$ 37	$ 88	$ 67	$ 68	$ 251	$ 227	$ 487
Income (loss) from divested businesses	(3)	(2)	(25)	(8)	(241)	13	60	100	38	68	545
Federal and foreign valuation allowance for deferred tax assets	(21)	5	7	30	40	24	(8)	(13)
Gain (Loss) on extinguishment of debt	(3)	1	5	4	(1)	1	(4)	(1)	(7)	5	(74)
Total prior year (favourable) unfavorable development	546	949	(26)	(40)	212	901	391	61
Restructuring and other costs	136	35	200	24	154	31	47	181
Impact of Tax Act	0	62	0	0	$ 6,687	$ 0	$ 0	$ 0	$ 62	$ 6,687	0
Adjustment
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
Income (loss) from continuing operations before income tax expense	(132)
Net income (loss) attributable to AIG	$ (87)	$ (40)	$ 0	$ 0
Adjustments 2016 [Member]
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
Income (loss) from continuing operations before income tax expense											(57)
Net income (loss) attributable to AIG											$ (174)