RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE INCOME - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (372)	$ (648)
Other comprehensive loss before reclassifications	155	130
Other-than-temporary impairment not recognized in earnings on securities, net of income taxes	(19)	(19)
Amounts reclassified from other comprehensive income	(4)	(6)
Net other comprehensive (loss) income	132	105
Ending balance	(240)	(543)
Net Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(69)	(298)
Other comprehensive loss before reclassifications	65	59
Other-than-temporary impairment not recognized in earnings on securities, net of income taxes	0	0
Amounts reclassified from other comprehensive income	(2)	7
Net other comprehensive (loss) income	63	66
Ending balance	(6)	(232)
Net Unrealized Gains (Losses) on Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	74	(91)
Other comprehensive loss before reclassifications	90	71
Other-than-temporary impairment not recognized in earnings on securities, net of income taxes	(19)	(19)
Amounts reclassified from other comprehensive income	(4)	(14)
Net other comprehensive (loss) income	67	38
Ending balance	141	(53)
Defined Benefit Pension Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(377)	(259)
Other comprehensive loss before reclassifications	0	0
Other-than-temporary impairment not recognized in earnings on securities, net of income taxes	0	0
Amounts reclassified from other comprehensive income	2	1
Net other comprehensive (loss) income	2	1
Ending balance	$ (375)	$ (258)