Quarterly report pursuant to Section 13 or 15(d)

Our Portfolio - Analysis of Portfolio by Type of Obligor and Credit Quality (Footnotes) (Details)

v3.10.0.1
Our Portfolio - Analysis of Portfolio by Type of Obligor and Credit Quality (Footnotes) (Details)
$ in Millions
9 Months Ended
Sep. 30, 2018
USD ($)
transaction
Financing Receivable, Recorded Investment [Line Items]  
Number of transactions | transaction 160
Financial receivable outstanding $ 11
Total aggregate remaining balance 60
Maximum [Member]  
Financing Receivable, Recorded Investment [Line Items]  
Financial receivable outstanding 1
Commercial Investment Grade [Member]  
Financing Receivable, Recorded Investment [Line Items]  
Financial receivable outstanding 9
Investment Grade by Independent Rating Agency [Member]  
Financing Receivable, Recorded Investment [Line Items]  
Total financing receivable 9
U.S. Federal Government [Member]  
Financing Receivable, Recorded Investment [Line Items]  
Total financing receivable 389
State, Local, Institutions [Member]  
Financing Receivable, Recorded Investment [Line Items]  
Total financing receivable 232
Residential Solar Loan [Member] | SunStrong [Member]  
Financing Receivable, Recorded Investment [Line Items]  
Loans receivable 110
Residential Solar Loan [Member] | Commercial Investment Grade [Member] | SunStrong [Member]  
Financing Receivable, Recorded Investment [Line Items]  
Total financing receivable $ 308