Schedule III Supplementary Insurance Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplementary Insurance Information, by Segment [Line Items]
Deferred Policy Acquisition Costs	$ 9,827	$ 9,436
Liability for Unpaid Claims and Claims Adjustment Expense, Future Policy Benefits	120,009	122,200
Reserve for Unearned Premiums	21,324	21,953
Policy and Contract Claims	829	806
Premiums and Policy Fees	39,869	39,839	40,381
Net Investment Income	16,079	15,810	20,343
Losses and Loss Expenses Incurred, Benefits	32,049	33,395	36,376
Amortization of Deferred Policy Acquisition Costs	5,330	5,157	5,709
Other Operating Expenses	10,887	10,883	10,639
Net Premiums Written	34,456	34,628	34,508
Corporate and Other
Supplementary Insurance Information, by Segment [Line Items]
Deferred Policy Acquisition Costs	18	23	25
Liability for Unpaid Claims and Claims Adjustment Expense, Future Policy Benefits	166	196	75
Reserve for Unearned Premiums	(1)	0	0
Policy and Contract Claims	11	10	9
Premiums and Policy Fees	72	76	118
Net Investment Income	604	(195)	4,918
Losses and Loss Expenses Incurred, Benefits	915	1,546	1,470
Amortization of Deferred Policy Acquisition Costs	59	(97)	167
Other Operating Expenses	6	8	6
Net Premiums Written	0	0	0
Non-life insurance companies
Supplementary Insurance Information, by Segment [Line Items]
Deferred Policy Acquisition Costs	2,551	2,493
Liability for Unpaid Claims and Claims Adjustment Expense, Future Policy Benefits	77,839	82,156
Reserve for Unearned Premiums	21,325	21,953
Policy and Contract Claims	0	0
Life insurance companies
Supplementary Insurance Information, by Segment [Line Items]
Deferred Policy Acquisition Costs	7,258	6,920
Liability for Unpaid Claims and Claims Adjustment Expense, Future Policy Benefits	42,004	39,848
Reserve for Unearned Premiums	0	0
Policy and Contract Claims	818	796
Commercial Insurance
Supplementary Insurance Information, by Segment [Line Items]
Premiums and Policy Fees	22,408	22,209	22,123
Net Investment Income	6,393	6,653	6,163
Losses and Loss Expenses Incurred, Benefits	16,985	17,415	19,441
Amortization of Deferred Policy Acquisition Costs	2,512	2,418	2,692
Other Operating Expenses	3,794	4,049	3,938
Net Premiums Written	22,044	21,928	21,206
Consumer Insurance
Supplementary Insurance Information, by Segment [Line Items]
Premiums and Policy Fees	17,389	17,554	18,140
Net Investment Income	9,082	9,352	9,262
Losses and Loss Expenses Incurred, Benefits	14,149	14,434	15,465
Amortization of Deferred Policy Acquisition Costs	2,759	2,836	2,850
Other Operating Expenses	7,087	6,826	6,695
Net Premiums Written	$ 12,412	$ 12,700	$ 13,302