Mortgage-Backed Securities - Percentage of Non-Agency RMBS By Year Originated (Details) - Non-Agency RMBS	Mar. 31, 2025	Dec. 31, 2024
Origination Year as a Percentage of Outstanding Principal Balance:
Percentage of underlying mortgages, year originated	100.00%	100.00%
2003 and prior
Origination Year as a Percentage of Outstanding Principal Balance:
Percentage of underlying mortgages, year originated	1.00%	0.90%
2004
Origination Year as a Percentage of Outstanding Principal Balance:
Percentage of underlying mortgages, year originated	0.70%	0.70%
2005
Origination Year as a Percentage of Outstanding Principal Balance:
Percentage of underlying mortgages, year originated	6.40%	7.00%
2006
Origination Year as a Percentage of Outstanding Principal Balance:
Percentage of underlying mortgages, year originated	39.50%	39.00%
2007
Origination Year as a Percentage of Outstanding Principal Balance:
Percentage of underlying mortgages, year originated	29.40%	29.40%
2008 and later
Origination Year as a Percentage of Outstanding Principal Balance:
Percentage of underlying mortgages, year originated	23.00%	23.00%