XML 83 R71.htm IDEA: XBRL DOCUMENT v3.7.0.1
Allowance for Credit Losses - Summary of Changes in Allowance for Credit Losses and Related Loan Balance by Product - Additional Information (Detail) - USD ($)
$ in Millions
Mar. 31, 2017
Dec. 31, 2016
Mar. 31, 2016
Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]        
Loans $ 69,588 $ 73,875 $ 81,732  
Allowance for credit losses 921 1,017 1,023 $ 912
TDR loans carried at lower of amortized cost or fair value less cost to sell 681 672 771  
Affiliated Entity [Member]        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Loans 939 3,274 5,107  
Commercial Loan [Member]        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Loans $ 49,996 $ 54,216    
Loans Reclassified to Global Banking [Member] | Commercial Loan [Member]        
Financing Receivable, Allowance for Credit Losses [Line Items]        
Loans     4,700  
Allowance for credit losses     $ 28