v3.26.1
Bonds and Notes Payable - Schedule of Outstanding Debt Obligations (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Debt Instrument [Line Items]    
Bonds and notes payable, gross $ 7,079,177 $ 7,821,569
Discount on bonds and notes payable and debt issuance costs (36,021) (40,642)
Bonds and notes payable, net 7,043,156 7,780,927
Unsecured line of credit    
Debt Instrument [Line Items]    
Bonds and notes payable, gross $ 0 $ 0
Interest rate 0.00% 0.00%
Participation agreements    
Debt Instrument [Line Items]    
Bonds and notes payable, gross $ 796 $ 1,322
Federally insured | Bonds and notes based on indices    
Debt Instrument [Line Items]    
Bonds and notes payable, gross 5,520,346 6,448,212
Federally insured | Bonds and notes based on auction    
Debt Instrument [Line Items]    
Bonds and notes payable, gross 10,915 24,150
Federally insured | Variable-rate bonds and notes    
Debt Instrument [Line Items]    
Bonds and notes payable, gross 5,531,261 6,472,362
Federally insured | Fixed rate bonds and notes    
Debt Instrument [Line Items]    
Bonds and notes payable, gross 277,696 302,791
Federally insured | Warehouse facilities    
Debt Instrument [Line Items]    
Bonds and notes payable, gross 469,041 213,982
Consumer loan warehouse and other facilities | Warehouse facilities    
Debt Instrument [Line Items]    
Bonds and notes payable, gross 752,435 767,951
Private education | Variable-rate bonds and notes    
Debt Instrument [Line Items]    
Bonds and notes payable, gross 27,414 35,770
Private education | Fixed rate bonds and notes    
Debt Instrument [Line Items]    
Bonds and notes payable, gross $ 20,534 $ 27,391
Interest rate 7.15%  
Minimum | Participation agreements    
Debt Instrument [Line Items]    
Interest rate 4.37% 4.53%
Minimum | Federally insured | Bonds and notes based on indices    
Debt Instrument [Line Items]    
Interest rate 3.99% 4.35%
Minimum | Federally insured | Bonds and notes based on auction    
Debt Instrument [Line Items]    
Interest rate 4.74% 0.01%
Minimum | Federally insured | Fixed rate bonds and notes    
Debt Instrument [Line Items]    
Interest rate 1.42% 1.42%
Minimum | Federally insured | Warehouse facilities    
Debt Instrument [Line Items]    
Interest rate 4.72% 4.83%
Minimum | Consumer loan warehouse and other facilities | Warehouse facilities    
Debt Instrument [Line Items]    
Interest rate 4.92% 5.01%
Minimum | Private education | Variable-rate bonds and notes    
Debt Instrument [Line Items]    
Interest rate 5.15% 5.15%
Minimum | Private education | Fixed rate bonds and notes    
Debt Instrument [Line Items]    
Interest rate   7.15%
Maximum | Participation agreements    
Debt Instrument [Line Items]    
Interest rate 5.82% 5.82%
Maximum | Federally insured | Bonds and notes based on indices    
Debt Instrument [Line Items]    
Interest rate 5.76% 5.85%
Maximum | Federally insured | Bonds and notes based on auction    
Debt Instrument [Line Items]    
Interest rate   5.10%
Maximum | Federally insured | Fixed rate bonds and notes    
Debt Instrument [Line Items]    
Interest rate 3.45% 3.45%
Maximum | Federally insured | Warehouse facilities    
Debt Instrument [Line Items]    
Interest rate 4.73% 4.84%
Maximum | Consumer loan warehouse and other facilities | Warehouse facilities    
Debt Instrument [Line Items]    
Interest rate 5.42% 5.67%
Maximum | Private education | Variable-rate bonds and notes    
Debt Instrument [Line Items]    
Interest rate 5.88% 6.12%