v3.5.0.2
Fair Value Measurements - Additional Information (Details) - USD ($)
9 Months Ended
Sep. 30, 2016
Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value on a nonrecurring basis $ 0  
Impaired loans measured at nonrecurring basis When the fair value of the collateral is based on an observable market price or a current appraised value, we measure the impaired loan at nonrecurring Level 2. When an appraised value is not available, or management determines the fair value of the collateral is further impaired below the appraised value and there is no observable market price or a discounted cash flow has been used to determine the fair value, we measure the impaired loan at nonrecurring Level 3.  
Borrowings $ 951,000,000 $ 796,000,000
Fair Value Measurement Level 3    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Prepayment rate 15.00%  
Fair Value Measurement Level 3 | Minimum    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Discount rate 4.00%  
Fair Value Measurement Level 3 | Maximum    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Discount rate 10.00%  
Fair Value Measurement Level 2    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Borrowings $ 951,000,000 $ 796,000,000