SHAREHOLDERS' EQUITY - Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales and redemptions		$ 26	$ 33	$ 186	$ 171
Other than temporary impairment losses realized	[1]	(137)	0	(143)	(31)
Total before tax		864	1,074	2,752	3,416
Income tax (expense) or benefit		(297)	(368)	(949)	(1,168)
Net of tax		$ 567	$ 706	$ 1,803	$ 2,248
The expected U.S. tax rate		35.00%	35.00%	35.00%	35.00%
Reclassification Out Of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax		$ (90)	$ 17	$ (14)	$ 13
Reclassification Out Of Accumulated Other Comprehensive Income | Unrealized gains (losses) on investment securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales and redemptions		(1)	27	123	21
Other than temporary impairment losses realized		(137)	0	(143)	(3)
Total before tax		(138)	27	(20)	18
Income tax (expense) or benefit	[2]	48	(9)	7	(6)
Net of tax		(90)	18	(13)	12
Reclassification Out Of Accumulated Other Comprehensive Income | Pension liability adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Acquisition and operating expenses, actuarial gains (losses)	[3]	(4)	(5)	(13)	(11)
Acquisition and operating expenses, prior service (cost) credit	[3]	4	4	12	13
Income tax (expense) or benefit	[2]	0	0	0	(1)
Net of tax		$ 0	$ (1)	$ (1)	$ 1

[1] Includes $6 and $0 for the three-month periods and $12 and $31 for the nine-month periods ended September 30, 2015 and 2014, respectively, from change in intent to sell securities; and $131 for the three- and nine-month periods ended September 30, 2015, for credit-related impairment

[2] Based on 35% tax rate

[3] These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 10 for additional details).