SHAREHOLDERS' EQUITY - Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales and redemptions										$ 303	$ 215	$ 262
Other-than-temporary impairment losses realized	[1]									(153)	(31)	(199)
Total before tax		$ 1,110	$ 864	$ 874	$ 1,013	$ 1,075	$ 1,074	$ 1,238	$ 1,104	3,862	4,491	4,816
Income Tax (Expense) Benefit		$ (380)	$ (297)	$ (301)	$ (350)	$ (372)	$ (368)	$ (428)	$ (372)	(1,329)	(1,540)	(1,658)
Net of tax										$ 2,533	$ 2,951	$ 3,158
The expected U.S. tax rate										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										$ 40	$ 36	$ 31
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										214	57	255
Other-than-temporary impairment losses realized										(153)	(3)	(199)
Total before tax										61	54	56
Income Tax (Expense) Benefit	[2]									(21)	(19)	(20)
Net of tax										40	35	36
Reclassification out of Accumulated Other Comprehensive Income | Pension liability adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Acquisition and operating expense, actuarial gains (losses)	[3]									(17)	(15)	(19)
Acquisition and operating expenses, prior service (cost) credit	[3]									17	17	4
Income Tax (Expense) Benefit	[2]									0	(1)	5
Net of tax										$ 0	$ 1	(10)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized foreign currency translation gains (losses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Sales and redemptions												7
Income Tax (Expense) Benefit	[2]											(2)
Net of tax												$ 5

[1] Includes $131 and $45 for the years ended December 31, 2015 and 2013, respectively, for credit-related impairments; $26 for the year ended December 31, 2013 for impairments due to severity and duration of decline in fair value; and $22, $31 and $128 for the years ended December 31, 2015, 2014 and 2013, respectively, from change in intent to sell securities

[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 14 for additional details).