XML 83 R63.htm IDEA: XBRL DOCUMENT v3.6.0.2
Investment Securities (Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Securities, Available for Sale) (Details) - USD ($)
$ in Millions
Dec. 31, 2016
Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost $ 77,627 $ 65,860
Available for sale securities: Gross Unrealized Gains 176 218
Available for sale securities: Gross Unrealized Losses 438 432
Available for sale securities: Fair Value 77,365 65,646 [1]
U.S. agency mortgage-backed securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 33,167 22,014
Available for sale securities: Gross Unrealized Gains 120 183
Available for sale securities: Gross Unrealized Losses 92 48
Available for sale securities: Fair Value 33,195 22,149
Asset-backed securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 20,520 21,784
Available for sale securities: Gross Unrealized Gains 29 7
Available for sale securities: Gross Unrealized Losses 214 306
Available for sale securities: Fair Value 20,335 21,485
Corporate debt securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 9,850 10,764
Available for sale securities: Gross Unrealized Gains 20 14
Available for sale securities: Gross Unrealized Losses 18 31
Available for sale securities: Fair Value 9,852 10,747
U.S. Treasury securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 8,679 5,719
Available for sale securities: Gross Unrealized Gains 3 2
Available for sale securities: Gross Unrealized Losses 59 17
Available for sale securities: Fair Value 8,623 5,704
Certificates of deposit [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 2,070 1,685
Available for sale securities: Gross Unrealized Gains 2 1
Available for sale securities: Gross Unrealized Losses 1 3
Available for sale securities: Fair Value 2,071 1,683
U.S. agency notes [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 1,915 3,177
Available for sale securities: Gross Unrealized Gains
Available for sale securities: Gross Unrealized Losses 8 27
Available for sale securities: Fair Value 1,907 3,150
U.S. state and municipal securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 1,167 414
Available for sale securities: Gross Unrealized Gains 2 10
Available for sale securities: Gross Unrealized Losses 46
Available for sale securities: Fair Value 1,123 424
Commercial paper [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 214  
Available for sale securities: Gross Unrealized Gains  
Available for sale securities: Gross Unrealized Losses  
Available for sale securities: Fair Value 214  
Non-agency commercial mortgage-backed securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost 45 298
Available for sale securities: Gross Unrealized Gains 1
Available for sale securities: Gross Unrealized Losses
Available for sale securities: Fair Value $ 45 299
Other securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities: Amortized Cost   5
Available for sale securities: Gross Unrealized Gains  
Available for sale securities: Gross Unrealized Losses  
Available for sale securities: Fair Value   $ 5
[1] Adjusted for the retrospective adoption of ASU 2015-03. See New Accounting Standards in Note 2 for additional information.