Quarterly report [Sections 13 or 15(d)]

Derivative Instruments and Hedging Activities - Derivative Instruments in Statement of Financial Position, Fair Value (Details)

v3.26.1
Derivative Instruments and Hedging Activities - Derivative Instruments in Statement of Financial Position, Fair Value (Details) - USD ($)
Mar. 31, 2026
Dec. 31, 2025
TBAs    
Notional Disclosures [Abstract]    
Notional $ (3,019,003,000) $ (4,206,715,000)
Futures, net    
Derivative, Fair Value, Net [Abstract]    
Fair Value 0 0
Notional Disclosures [Abstract]    
Notional (6,354,300,000) (4,357,800,000)
Interest rate lock commitments    
Derivative, Fair Value, Net [Abstract]    
Fair Value 800,000 900,000
Notional Disclosures [Abstract]    
Notional (65,800,000) (49,600,000)
Derivative Assets    
Derivative, Fair Value, Net [Abstract]    
Fair Value 71,213,000 87,549,000
Notional Disclosures [Abstract]    
Notional (3,207,671,000) (2,601,018,000)
Derivative Assets | Inverse interest-only securities    
Derivative, Fair Value, Net [Abstract]    
Fair Value 64,352,000 68,303,000
Notional Disclosures [Abstract]    
Notional (1,165,070,000) (1,233,247,000)
Derivative Assets | Interest rate swap agreements    
Derivative, Fair Value, Net [Abstract]    
Fair Value 0 0
Notional Disclosures [Abstract]    
Notional 0 0
Derivative Assets | TBAs    
Derivative, Fair Value, Net [Abstract]    
Fair Value 6,065,000 18,365,000
Notional Disclosures [Abstract]    
Notional (1,925,315,000) (5,676,000,000)
Derivative Assets | Futures, net    
Derivative, Fair Value, Net [Abstract]    
Fair Value 0 0
Notional Disclosures [Abstract]    
Notional (6,354,300,000) (4,357,800,000)
Derivative Assets | Interest rate lock commitments    
Derivative, Fair Value, Net [Abstract]    
Fair Value 796,000 881,000
Notional Disclosures [Abstract]    
Notional (56,244,000) (49,571,000)
Derivative Liabilities    
Derivative, Fair Value, Net [Abstract]    
Fair Value (11,254,000) (4,254,000)
Notional Disclosures [Abstract]    
Notional (12,538,946,000) (11,110,701,000)
Derivative Liabilities | Inverse interest-only securities    
Derivative, Fair Value, Net [Abstract]    
Fair Value 0 0
Notional Disclosures [Abstract]    
Notional 0 0
Derivative Liabilities | Interest rate swap agreements    
Derivative, Fair Value, Net [Abstract]    
Fair Value 0 0
Notional Disclosures [Abstract]    
Notional (11,435,749,000) (12,579,986,000)
Derivative Liabilities | TBAs    
Derivative, Fair Value, Net [Abstract]    
Fair Value (11,228,000) (4,254,000)
Notional Disclosures [Abstract]    
Notional (1,093,688,000) (1,469,285,000)
Derivative Liabilities | Futures, net    
Derivative, Fair Value, Net [Abstract]    
Fair Value 0 0
Notional Disclosures [Abstract]    
Notional 0 0
Derivative Liabilities | Interest rate lock commitments    
Derivative, Fair Value, Net [Abstract]    
Fair Value (26,000) 0
Notional Disclosures [Abstract]    
Notional $ (9,509,000) $ 0