v3.10.0.1
Fair Value Measurement - Schedule of Fair Value of Financial Instruments (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Financial assets:    
Securities held to maturity $ 36,619 $ 29,437
Level 1    
Financial assets:    
Cash and cash equivalents 4,768 4,458
Restricted cash for securitization investors 303 312
Securities held to maturity 0 200
Net loans held for investment 0 0
Loans held for sale 0 0
Interest receivable 0 0
Other investments 0 0
Financial liabilities:    
Deposits with defined maturities 0  
Deposits   26,404
Securitized debt obligations 0 0
Senior and subordinated notes 0 0
Federal funds purchased and securities loaned or sold under agreements to repurchase 0 0
Other borrowings 0 0
Interest payable 0 0
Level 2    
Financial assets:    
Cash and cash equivalents 8,418 9,582
Restricted cash for securitization investors 0 0
Securities held to maturity 36,513 29,217
Net loans held for investment 0 0
Loans held for sale 1,218 949
Interest receivable 1,614 1,536
Other investments 1,725 1,680
Financial liabilities:    
Deposits with defined maturities 38,279  
Deposits   217,328
Securitized debt obligations 18,359 20,122
Senior and subordinated notes 30,635 31,392
Federal funds purchased and securities loaned or sold under agreements to repurchase 352 576
Other borrowings 9,354 8,892
Interest payable 458 413
Level 3    
Financial assets:    
Cash and cash equivalents 0 0
Restricted cash for securitization investors 0 0
Securities held to maturity 106 20
Net loans held for investment 241,556 251,468
Loans held for sale 0 3
Interest receivable 0 0
Other investments 0 9
Financial liabilities:    
Deposits with defined maturities 0  
Deposits   0
Securitized debt obligations 0 0
Senior and subordinated notes 0 0
Federal funds purchased and securities loaned or sold under agreements to repurchase 0 0
Other borrowings 0 0
Interest payable 0 0
Carrying Value    
Financial assets:    
Cash and cash equivalents 13,186 14,040
Restricted cash for securitization investors 303 312
Securities held to maturity 36,771 28,984
Net loans held for investment 238,679 246,971
Loans held for sale 1,192 971
Interest receivable 1,614 1,536
Other investments 1,725 1,689
Financial liabilities:    
Deposits with defined maturities 38,471  
Deposits   243,702
Securitized debt obligations 18,307 20,010
Senior and subordinated notes 30,826 30,755
Federal funds purchased and securities loaned or sold under agreements to repurchase 352 576
Other borrowings 9,354 8,892
Interest payable 458 413
Estimated Fair Value    
Financial assets:    
Cash and cash equivalents 13,186 14,040
Restricted cash for securitization investors 303 312
Securities held to maturity 36,619 29,437
Net loans held for investment 241,556 251,468
Loans held for sale 1,218 952
Interest receivable 1,614 1,536
Other investments 1,725 1,689
Financial liabilities:    
Deposits with defined maturities 38,279  
Deposits   243,732
Securitized debt obligations 18,359 20,122
Senior and subordinated notes 30,635 31,392
Federal funds purchased and securities loaned or sold under agreements to repurchase 352 576
Other borrowings 9,354 8,892
Interest payable $ 458 $ 413