v3.26.1
Derivative Instruments and Hedging Activities - TBA Contracts (Details) - USD ($)
Jun. 30, 2026
Dec. 31, 2025
Balance Sheet Location [Axis]: us-gaap:DerivativeAssets    
Derivative [Line Items]    
Notional $ 4,316,594,000 $ 2,601,018,000
Net carrying value 69,366,000 87,549,000
Balance Sheet Location [Axis]: us-gaap:DerivativeLiabilities    
Derivative [Line Items]    
Notional 6,651,884,000 11,110,701,000
Net carrying value (1,891,000) (4,254,000)
TBAs    
Derivative [Line Items]    
Notional 3,828,003,000 4,206,715,000
Cost Basis 3,802,578,000 4,185,465,000
Market value 3,814,318,000 4,199,576,000
TBAs | Balance Sheet Location [Axis]: us-gaap:DerivativeAssets    
Derivative [Line Items]    
Notional 3,215,696,000 5,676,000,000
Net carrying value 13,631,000 18,365,000
TBAs | Balance Sheet Location [Axis]: us-gaap:DerivativeLiabilities    
Derivative [Line Items]    
Notional 612,307,000 1,469,285,000
Net carrying value (1,891,000) (4,254,000)
TBAs | Purchase contracts    
Derivative [Line Items]    
Notional 4,105,003,000 5,676,000,000
Cost Basis 4,087,587,000 5,689,566,000
Market value 4,099,793,000 5,707,931,000
TBAs | Purchase contracts | Balance Sheet Location [Axis]: us-gaap:DerivativeAssets    
Derivative [Line Items]    
Net carrying value 13,631,000 18,365,000
TBAs | Purchase contracts | Balance Sheet Location [Axis]: us-gaap:DerivativeLiabilities    
Derivative [Line Items]    
Net carrying value (1,425,000) 0
TBAs | Sale contracts    
Derivative [Line Items]    
Notional 277,000,000 1,469,285,000
Cost Basis 285,009,000 1,504,101,000
Market value 285,475,000 1,508,355,000
TBAs | Sale contracts | Balance Sheet Location [Axis]: us-gaap:DerivativeAssets    
Derivative [Line Items]    
Net carrying value 0 0
TBAs | Sale contracts | Balance Sheet Location [Axis]: us-gaap:DerivativeLiabilities    
Derivative [Line Items]    
Net carrying value $ (466,000) $ (4,254,000)