Variable Interest Entities - Unpaid Principal (Details) - Variable Interest Entity, Primary Beneficiary [Member] - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
FG VIEs’ assets	$ 312	$ 279
FG VIEs' liabilities with recourse	30	21
FG VIEs’ liabilities without recourse	38	19
Unpaid principal balance for FG VIEs’ assets that were 90 days or more past due	49	52
Unpaid principal for FG VIEs’ liabilities with recourse	$ 362	$ 388