Securitizations and Variable Interest Entities - Schedule of Expected Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Carrying Value	$ 98,780	$ 0
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Carrying Value	98,780
Total Exposure	98,780
Rated notes | Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Carrying Value	85,234
Total Exposure	85,234
Certificates and other assets | Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Carrying Value	13,546
Total Exposure	$ 13,546