Loans Held for Investment - By Region (Details)	Dec. 31, 2021	Dec. 31, 2020
Loans held for investment by Region [Line Items]
Percentage of Loans concentrated in major states	38.40%	38.80%
New York
Loans held for investment by Region [Line Items]
Percentage of Loans held in state	9.40%	9.70%
California
Loans held for investment by Region [Line Items]
Percentage of Loans held in state	9.60%	9.60%
Pennsylvania
Loans held for investment by Region [Line Items]
Percentage of Loans held in state	7.80%	8.00%
New Jersey
Loans held for investment by Region [Line Items]
Percentage of Loans held in state	6.00%	6.20%
Texas
Loans held for investment by Region [Line Items]
Percentage of Loans held in state	5.60%	5.30%