CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 220	$ 189	$ 619	$ 668
Other comprehensive income (loss):
Net unrealized derivative instrument gains arising during the periods, net of income taxes of $30, $10, $66 and $80, respectively	48	17	108	137
Reclassification adjustment for net derivative (losses) gains included in net income, net of income taxes of ($3), $2, ($5) and $9, respectively	(4)	3	(8)	16
Net unrealized securities available for sale gains (losses) arising during the periods, net of income taxes of $37, ($36), $25 and $73, respectively	61	(61)	41	127
Other-than-temporary impairment not recognized in earnings on securities, net of income taxes of ($4), $0, ($15) and ($12), respectively	(8)	(1)	(26)	(22)
Reclassification of net securities gains to net income, net of income taxes of $0, $0, ($5) and ($7), respectively	0	(1)	(9)	(13)
Defined benefit pension plans:
Actuarial loss, net of income taxes of $0, ($35), $0 and ($35), respectively	0	(59)	0	(59)
Net prior service credit, net of income taxes of $0, $3, $0 and $3, respectively	0	4	0	4
Amortization of actuarial loss, net of income taxes $0, $1, $3 and $2, respectively	3	2	7	4
Divestitures to RBS effective September 1, 2014, net of income taxes of $0, $13, $0 and $13, respectively	0	19	0	19
Total other comprehensive income (loss), net of income taxes	100	(77)	113	213
Total comprehensive income	$ 320	$ 112	$ 732	$ 881