Fair Value Measurements - Unobservable Inputs Assumptions - Loans Held for Investment (Details) - Loans Held for Investment at Fair Value - Level 3	Dec. 31, 2022	Dec. 31, 2021
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Coupon	5.80%	6.10%
FICO	656	654
Loan-to-value (LTV)	82.00%	84.00%
Single family
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	80.00%	83.00%
Manufactured housing
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	3.00%	4.00%
Multi-family/mixed use/other
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	17.00%	13.00%
Owner Occupied
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	89.00%	91.00%
Investor
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	5.00%	3.00%
Secondary
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average percent	6.00%	6.00%
Base Rate
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Coupon	6.30%	3.10%
FICO	640	640
Loan-to-value (LTV)	87.00%	87.00%