Annual report pursuant to Section 13 and 15(d)

Securitization of Receivables - Additional Information (Details)

v3.10.0.1
Securitization of Receivables - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]      
Managed assets $ 5,300,000,000 $ 4,700,000,000  
Securitization credit losses 0 0 $ 0
Greater than 90 Days Past Due [Member]      
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]      
Payment from debtors to securitization trust 2,600,000    
Asset-backed Securities, Securitized Loans and Receivables [Member]      
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]      
Managed receivables $ 3,300,000,000 $ 2,700,000,000  
Minimum [Member]      
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]      
Discount rates to determine fair market value of underlying assets 4.00%    
Maximum [Member]      
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]      
Annual servicing fees (as a percent) 0.20%    
Discount rates to determine fair market value of underlying assets 7.00%