v3.26.1
Investments and Notes Receivable - Schedule of Investments Classified by Contractual Maturity Date (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less $ 40,857  
Amortized cost, after 1 year through 5 years 35,713  
Amortized cost, after 5 years through 10 years 228,002  
Amortized cost, after 10 years 1,276,291  
Amortized cost 1,580,863  
Fair value    
Fair value, 1 year or less 40,572  
Fair value, after 1 year through 5 years 35,738  
Fair value, after 5 years through 10 years 227,826  
Fair value, after 10 years 1,274,204  
Total 1,578,340  
Held-to-maturity asset-backed securities    
Total 210,908  
Fair value    
Total 214,973  
Beneficial interest in loan securitizations    
Amortized cost, 1 year or less 0  
Amortized cost, after 1 year through 5 years 0  
Amortized cost, after 5 years through 10 years 0  
Amortized cost, after 10 years 0  
Beneficial interest in securitizations 188,852 $ 194,830
Fair value    
Fair value, 1 year or less 0  
Fair value, after 1 year through 5 years 0  
Fair value, after 5 years through 10 years 0  
Fair value, after 10 years 0  
Beneficial Interest In Securitization, Fair Value Disclosure 202,812  
Total Non-Nelnet Bank    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 100  
Amortized cost, after 1 year through 5 years 6,364  
Amortized cost, after 5 years through 10 years 68,485  
Amortized cost, after 10 years 453,004  
Amortized cost 527,953 463,005
Fair value    
Fair value, 1 year or less 100  
Fair value, after 1 year through 5 years 6,446  
Fair value, after 5 years through 10 years 68,319  
Fair value, after 10 years 448,593  
Total 523,458 457,999
FFELP loan    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 0  
Amortized cost, after 1 year through 5 years 206  
Amortized cost, after 5 years through 10 years 2,543  
Amortized cost, after 10 years 40,717  
Amortized cost 43,466 36,824
Fair value    
Total 46,198 39,645
FFELP loan and other debt securities - restricted    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 0  
Amortized cost, after 1 year through 5 years 6,158  
Amortized cost, after 5 years through 10 years 54,040  
Amortized cost, after 10 years 132,189  
Amortized cost 192,387 172,739
Fair value    
Total 194,770 175,800
Private education loan    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 0  
Amortized cost, after 1 year through 5 years 0  
Amortized cost, after 5 years through 10 years 215  
Amortized cost, after 10 years 177,084  
Amortized cost 177,299 197,568
Fair value    
Total 165,131 184,152
Other debt securities    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 100  
Amortized cost, after 1 year through 5 years 0  
Amortized cost, after 5 years through 10 years 11,687  
Amortized cost, after 10 years 103,014  
Amortized cost 114,801 55,874
Fair value    
Total 117,359 58,402
Total Nelnet Bank    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 40,757  
Amortized cost, after 1 year through 5 years 29,349  
Amortized cost, after 5 years through 10 years 159,517  
Amortized cost, after 10 years 823,287  
Amortized cost 1,052,910 841,359
Fair value    
Fair value, 1 year or less 40,472  
Fair value, after 1 year through 5 years 29,292  
Fair value, after 5 years through 10 years 159,507  
Fair value, after 10 years 825,611  
Total 1,054,882 846,989
FFELP loan    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 40,757  
Amortized cost, after 1 year through 5 years 11,913  
Amortized cost, after 5 years through 10 years 17,536  
Amortized cost, after 10 years 173,798  
Amortized cost 244,004 258,208
Fair value    
Total 249,335 263,923
Private education loan    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 0  
Amortized cost, after 1 year through 5 years 0  
Amortized cost, after 5 years through 10 years 11,720  
Amortized cost, after 10 years 95  
Amortized cost 11,815 13,623
Fair value    
Total 11,780 13,586
Other debt securities    
Available-for-sale asset-backed securities    
Amortized cost, 1 year or less 0  
Amortized cost, after 1 year through 5 years 17,436  
Amortized cost, after 5 years through 10 years 130,261  
Amortized cost, after 10 years 649,394  
Amortized cost 797,091 569,528
Fair value    
Total 793,767 569,480
FFELP loan    
Held-to-maturity asset-backed securities    
Amortized cost, 1 year or less 0  
Amortized cost, after 1 year through 5 years 2,337  
Amortized cost, after 5 years through 10 years 12,404  
Amortized cost, after 10 years 196,167  
Total 210,908 $ 211,299
Fair value    
Fair value, 1 year or less 0  
Fair value, after 1 year through 5 years 2,336  
Fair value, after 5 years through 10 years 12,201  
Fair value, after 10 years 200,436  
Total $ 214,973