Schedule II Condensed Financial Information of Registrant - Parent Company Only (Details - Statements of Cash Flows) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ (8,585)	$ 2,383	$ 2,877
Cash flows from investing activities:
Sale of divested businesses, net	792	2,809	0
Purchase of investments	(63,246)	(69,985)	(65,265)
Net change in restricted cash	(121)	385	1,457
Net change in short-term investments	2,098	(3,089)	1,163
Contributions from (to) subsidiaries - net	0	0
Mortgage and other loans receivable	(9,369)	(10,651)	(10,140)
Payments received on mortgages and other loan receivables	5,742	6,074	5,104
Loans to subsidiaries - net	0	0
Other, net	(2,143)	(1,020)	(1,509)
Net cash provided by (used in) investing activities	14,671	4,744	8,462
Cash flows from financing activities:
Issuance of long-term debt	3,356	5,954	6,867
Repayments of long-term debt	(3,698)	(4,082)	(9,805)
Cash dividends paid	(1,172)	(1,372)	(1,028)
Purchase of Common Stock	(6,275)	(11,460)	(10,691)
Other, net	31	(68)	(818)
Net cash provided by (used in) financing activities	(5,697)	(6,833)	(11,429)
Net increase (decrease) in cash	361	346	(129)
Cash at beginning of year	1,868	1,629	1,758
Cash at end of Period	2,362	1,868	1,629
Interest:
Third party	(1,282)	(1,331)	(1,368)
Intercompany	0	0	0
Taxes:
Income tax authorities	(544)	(493)	(511)
Intercompany	0	0	0
Aer Cap
Non-cash investing/financing activities:
Non-cash consideration received from sale	0	0	500
United Guaranty Corporation
Non-cash investing/financing activities:
Non-cash consideration received from sale	0	1,101	0
Parent Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	36	2,112	4,443
Cash flows from investing activities:
Sales and maturities of investments	5,714	5,598	7,609
Sale of divested businesses, net	40	2,160	0
Purchase of investments	(2,465)	(1,002)	(1,881)
Net change in short-term investments	1,990	(789)	2,300
Contributions from (to) subsidiaries - net	2,446	1,637	565
Mortgage and other loans receivable	0	(85)	0
Payments received on mortgages and other loan receivables	107	171	158
Loans to subsidiaries - net	199	1,525	(83)
Other, net	(183)	(56)	(175)
Net cash provided by (used in) investing activities	7,848	9,159	8,493
Cash flows from financing activities:
Issuance of long-term debt	1,505	3,831	5,540
Repayments of long-term debt	(1,724)	(1,996)	(6,504)
Cash dividends paid	(1,172)	(1,372)	(1,028)
Loans from subsidiaries - net	(63)	3	(201)
Purchase of Common Stock	(6,275)	(11,460)	(10,691)
Other, net	(154)	(309)	(44)
Net cash provided by (used in) financing activities	(7,883)	(11,303)	(12,928)
Net increase (decrease) in cash	1	(32)	8
Cash at beginning of year	2	34	26
Cash at end of Period	3	2	34
Interest:
Third party	(948)	(975)	(1,030)
Intercompany	0	2	0
Taxes:
Income tax authorities	(329)	(15)	(11)
Intercompany	614	479	829
Non-cash investing/financing activities:
Other capital contributions - net	259	3,245	494
Return of capital	26	0	0
Dividends received in the form of securities	735	5,234	2,326
Fixed maturity securities received in exchange for equity securities	$ 0	$ 440	$ 0