Securities (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Securities available for sale
Amortized Cost	$ 16,318	$ 14,378
Gross Unrealized Gains	65	54
Gross Unrealized Losses	214	291
Fair Value	16,169	14,141
U.S. Treasury securities
Securities available for sale
Amortized Cost	2,331	2,625
Gross Unrealized Gains	0	1
Gross Unrealized Losses	89	121
Fair Value	2,242	2,505
Residential mortgage-backed securities, U.S. government agency and government-sponsored agencies
Securities available for sale
Amortized Cost	8,919	6,814
Gross Unrealized Gains	6	3
Gross Unrealized Losses	92	122
Fair Value	8,833	6,695
Residential mortgage-backed securities, Privately issued
Securities available for sale
Amortized Cost	501	333
Gross Unrealized Gains	2	1
Gross Unrealized Losses	4	7
Fair Value	499	327
Privately issued - commercial mortgage-backed securities
Securities available for sale
Amortized Cost	712	666
Gross Unrealized Gains	6	4
Gross Unrealized Losses	4	6
Fair Value	714	664
Collateralized loan obligations
Securities available for sale
Amortized Cost	2,227	2,219
Gross Unrealized Gains	5	4
Gross Unrealized Losses	2	5
Fair Value	2,230	2,218
Other Asset Liability Management Securities
Securities available for sale
Amortized Cost	7	7
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	7	7
Asset Liability Management securities
Securities available for sale
Amortized Cost	14,697	12,664
Gross Unrealized Gains	19	13
Gross Unrealized Losses	191	261
Fair Value	14,525	12,416
Other debt securities, Direct bank purchase bonds
Securities available for sale
Amortized Cost	1,523	1,601
Gross Unrealized Gains	46	41
Gross Unrealized Losses	23	29
Fair Value	1,546	1,613
Other debt securities, Other
Securities available for sale
Amortized Cost	93	108
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	1
Fair Value	93	107
Equities
Securities available for sale
Amortized Cost	5	5
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 5	$ 5

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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