Securitizations and Variable Interest Entities - Schedule of Cost and Fair Value of Securities (Details) - Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure $ in Thousands	Dec. 31, 2019 USD ($)
Variable Interest Entity [Line Items]
Amortized Cost	$ 98,439
Fair Value	98,780
Rated notes
Variable Interest Entity [Line Items]
Amortized Cost	84,983
Fair Value	85,234
Certificates and other assets
Variable Interest Entity [Line Items]
Amortized Cost	13,456
Fair Value	$ 13,546