Summary of Significant Accounting Policies - Residential Whole Loans (Details) - USD ($) $ in Millions |
6 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2025 |
Dec. 31, 2024 |
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| LTV ratio (as a percent) | 80.00% | |
| Residential whole loans | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| LTV ratio (as a percent) | 64.00% | |
| Residential whole loans | Business purpose loans | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| LTV ratio (as a percent) | 67.00% | 67.00% |
| Residential whole loans | Business purpose loans | Multifamily Properties | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Threshold balance (below) | $ 10 |