Selected Quarterly Financial Data (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net interest income	$ 588	$ 604	$ 638	$ 654	$ 621	$ 617	$ 626	$ 606	$ 2,484	[1]	$ 2,470	[1]	$ 2,304	[1]
Provision for credit losses	19	62	134	157	267	47	(6)	53	372	[2]	361		188
Net interest income after provision for credit losses	569	542	504	497	354	570	632	553	2,112		2,109		2,116
Other revenues	257	320	293	462	274	531	403	464	1,332		1,672		1,606
Operating expenses	874	803	823	726	808	786	850	777	3,226	[3]	3,221	[3]	3,424	[3]
Income before income tax	(48)	59	(26)	233	(180)	315	185	240	218		560		298
Income tax expense (benefit)	(11)	26	(5)	79	(55)	111	98	76	89		230		(56)
Net income	$ (37)	$ 33	$ (21)	$ 154	$ (125)	$ 204	$ 87	$ 164	$ 129		$ 330		$ 354

[1] Net interest income of each segment represents the difference between actual interest earned on assets and interest paid on liabilities of the segment adjusted for a funding charge or credit. Segments are charged a cost to fund assets (e.g. customer loans) and receive a funding credit for funds provided (e.g. customer deposits) based on equivalent market rates. The objective of these charges/credits is to transfer interest rate risk from the segments to one centralized unit in Balance Sheet Management and more appropriately reflect the profitability of the segments.

[2] The provision for credit losses and charge-offs for residential mortgage loans during 2016 includes $11 million related to the lower of amortized cost or fair value adjustment attributable to credit factors for loans transferred to held for sale. See Note 7, "Loans Held for Sale," for additional information.

[3] Expenses for the segments include fully apportioned corporate overhead expenses.