CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 840	$ 865	$ (3,426)
Other comprehensive income (loss):
Net unrealized derivative instrument gains (losses) arising during the periods, net of income taxes of $57, $122 and ($100), respectively	93	212	(172)
Reclassification adjustment for net derivative losses (gains) included in net income, net of income taxes of ($9), $10, and $66, respectively	(14)	17	114
Net unrealized securities available for sale (losses) gains arising during the periods, net of income taxes of ($38), $116, and ($165), respectively	(66)	198	(285)
Other-than-temporary impairment not recognized in earnings on securities, net of income taxes of ($14), ($13), and ($15), respectively	(22)	(22)	(26)
Reclassification of net securities gains to net income, net of income taxes of ($8), ($7), and ($50), respectively	(14)	(11)	(86)
Defined benefit pension plans:
Actuarial (loss) gain, net of income taxes of ($3), ($92), and $66, respectively	(3)	(148)	110
Net prior service credit, net of income taxes of $0, $3 and $0, respectively	0	4	0
Amortization of actuarial loss, net of income taxes $3, $3 and $5, respectively	12	7	9
Amortization of net prior service credit, net of income taxes $0, $0 and $0, respectively	(1)	(1)	0
Divestitures to RBS effective September 1, 2014, net of income taxes of $0, $12 and $0, respectively	0	20	0
Total other comprehensive (loss) income, net of income taxes	(15)	276	(336)
Total comprehensive income (loss)	$ 825	$ 1,141	$ (3,762)