Summary of Significant Accounting Policies, Nature of Operations and Other Developments Summary of Significant Accounting Policies, Nature of Operations and Other Developments(Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Depreciation, amortization and accretion, net	$ 80	$ 111
Payments for Origination and Purchases of Loans Held-for-sale	(519)	(362)
Net proceeds from sale of loans originated for sale	514	291
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	258	168
Proceeds from sales of loans	34	36
Payments for (Proceeds from) Loans and Leases	(1,620)	(91)
Net Cash Provided by (Used in) Investing Activities, Continuing Operations	(723)	(673)
Net cash provided by (used in) financing activities	4,260	(632)
Cash and Cash Equivalents, Period Increase (Decrease)	3,795	$ (1,137)
Transfer of Portfolio Loans and Leases to Held-for-sale	$ (81)