v3.26.3
Derivatives - Schedule of Interest Rate Hedging Instruments (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Interest rate swaps    
Derivative [Line Items]    
Fair Value $ 947,000  
Interest rate swaps | Long position | Not Designated as Hedging Instrument, Economic Hedge    
Derivative [Line Items]    
Derivative, Notional Amount $ (17,597,000) $ (9,685,000)
Derivative, average fixed interest rate 3.83% 3.66%
Interest rate swaps | Long position | Not Designated as Hedging Instrument, Economic Hedge | 3-5 years    
Derivative [Line Items]    
Derivative, Notional Amount $ (4,080,000) $ (2,450,000)
Derivative, average fixed interest rate 3.63% 3.42%
Interest rate swaps | Long position | Not Designated as Hedging Instrument, Economic Hedge | 5-7 years    
Derivative [Line Items]    
Derivative, Notional Amount $ (4,820,000) $ (4,070,000)
Derivative, average fixed interest rate 3.85% 3.66%
Interest rate swaps | Long position | Not Designated as Hedging Instrument, Economic Hedge | 7-10 years    
Derivative [Line Items]    
Derivative, Notional Amount $ (5,845,000) $ (3,090,000)
Derivative, average fixed interest rate 3.93% 3.87%
Interest rate swaps | Long position | Not Designated as Hedging Instrument, Economic Hedge | 10-15 years    
Derivative [Line Items]    
Derivative, Notional Amount $ (142,000) $ (75,000)
Derivative, average fixed interest rate 4.79% 3.77%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge    
Derivative [Line Items]    
Derivative, Notional Amount $ (17,597,000) $ (9,685,000)
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | 1-3 years    
Derivative [Line Items]    
Derivative, Notional Amount $ (1,925,000) $ 0
Derivative, average fixed interest rate 3.63% 0.00%
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | 15-20 years    
Derivative [Line Items]    
Derivative, Notional Amount $ (785,000) $ 0
Derivative, average fixed interest rate 4.39% 0.00%
U.S. Treasury futures    
Derivative [Line Items]    
Fair Value $ 240,000 $ 22,000
U.S. Treasury futures | Short position | 5-year    
Derivative [Line Items]    
Derivative, Notional Amount (650,000) (30,000)
U.S. Treasury futures | Short position | 10-year    
Derivative [Line Items]    
Derivative, Notional Amount (2,893,700) (1,475,000)
U.S. Treasury futures | Short position | 30-year    
Derivative [Line Items]    
Derivative, Notional Amount (3,132,800) (1,153,500)
U.S. Treasury futures | Short position | Not Designated as Hedging Instrument, Economic Hedge    
Derivative [Line Items]    
Derivative, Notional Amount (6,676,500) (2,658,500)
Exchange Traded Options | Long position | Not Designated as Hedging Instrument, Economic Hedge    
Derivative [Line Items]    
Derivative, Notional Amount $ 0 (500,000)
Fair Value   $ 2,657