Segment Information and Concentration - Segment Information and Concentration. - Top Ten Advance Holders and Associated Interest Income (Details) - USD ($)
$ in Thousands |
3 Months Ended |
9 Months Ended |
12 Months Ended |
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
Dec. 31, 2025 |
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
$ 120,469,286
|
|
$ 120,469,286
|
|
$ 92,466,404
|
| Interest Income |
1,279,638
|
$ 1,200,721
|
3,491,309
|
$ 3,667,872
|
|
| Par Advances | Credit Concentration Risk | Top Ten Advance Holders |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
92,079,708
|
67,947,111
|
$ 92,079,708
|
$ 67,947,111
|
$ 65,442,096
|
| Concentration risk percentage |
|
|
76.43%
|
70.48%
|
70.75%
|
| Par Advances | Credit Concentration Risk | Citibank, N.A. |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
30,000,000
|
12,000,000
|
$ 30,000,000
|
$ 12,000,000
|
$ 9,000,000
|
| Concentration risk percentage |
|
|
24.90%
|
12.45%
|
9.73%
|
| Par Advances | Credit Concentration Risk | MetLife, Inc.: |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
14,215,000
|
14,215,000
|
$ 14,215,000
|
$ 14,215,000
|
$ 14,215,000
|
| Concentration risk percentage |
|
|
11.80%
|
14.74%
|
15.37%
|
| Par Advances | Credit Concentration Risk | Metropolitan Life Insurance Company |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
12,835,000
|
12,835,000
|
$ 12,835,000
|
$ 12,835,000
|
$ 12,835,000
|
| Concentration risk percentage |
|
|
10.65%
|
13.31%
|
13.88%
|
| Par Advances | Credit Concentration Risk | Metropolitan Tower Life Insurance Company |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
1,380,000
|
1,380,000
|
$ 1,380,000
|
$ 1,380,000
|
$ 1,380,000
|
| Concentration risk percentage |
|
|
1.15%
|
1.43%
|
1.49%
|
| Par Advances | Credit Concentration Risk | Teachers Ins. and Annuity Assoc of America |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
11,521,200
|
6,846,100
|
$ 11,521,200
|
$ 6,846,100
|
$ 7,228,900
|
| Concentration risk percentage |
|
|
9.56%
|
7.10%
|
7.82%
|
| Par Advances | Credit Concentration Risk | Flagstar Bank, N.A. |
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|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
8,500,000
|
10,750,000
|
$ 8,500,000
|
$ 10,750,000
|
$ 9,750,000
|
| Concentration risk percentage |
|
|
7.06%
|
11.15%
|
10.54%
|
| Par Advances | Credit Concentration Risk | Equitable Financial Life Insurance Co. |
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|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
6,865,063
|
6,865,063
|
$ 6,865,063
|
$ 6,865,063
|
$ 6,865,063
|
| Concentration risk percentage |
|
|
5.70%
|
7.12%
|
7.42%
|
| Par Advances | Credit Concentration Risk | Manufacturers and Traders Trust Company |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
6,300,130
|
|
$ 6,300,130
|
|
|
| Concentration risk percentage |
|
|
5.23%
|
|
|
| Par Advances | Credit Concentration Risk | New York Life Insurance Company |
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|
|
|
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| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
4,788,000
|
3,988,000
|
$ 4,788,000
|
$ 3,988,000
|
$ 4,588,000
|
| Concentration risk percentage |
|
|
3.97%
|
4.14%
|
4.96%
|
| Par Advances | Credit Concentration Risk | Guardian Life Insurance Co. of America |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
3,714,110
|
3,200,094
|
$ 3,714,110
|
$ 3,200,094
|
$ 3,212,279
|
| Concentration risk percentage |
|
|
3.08%
|
3.32%
|
3.47%
|
| Par Advances | Credit Concentration Risk | Goldman Sachs Bank USA |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
3,500,000
|
5,000,000
|
$ 3,500,000
|
$ 5,000,000
|
$ 5,500,000
|
| Concentration risk percentage |
|
|
2.91%
|
5.19%
|
5.95%
|
| Par Advances | Credit Concentration Risk | ESL Federal Credit Union |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
$ 2,676,205
|
|
$ 2,676,205
|
|
|
| Concentration risk percentage |
|
|
2.22%
|
|
|
| Par Advances | Credit Concentration Risk | Prudential Insurance Company of America |
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|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
|
2,619,250
|
|
$ 2,619,250
|
$ 2,619,250
|
| Concentration risk percentage |
|
|
|
2.72%
|
2.83%
|
| Par Advances | Credit Concentration Risk | Valley National Bank |
|
|
|
|
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| Concentration Risk [Line Items] |
|
|
|
|
|
| Par Advances |
|
$ 2,463,604
|
|
$ 2,463,604
|
$ 2,463,604
|
| Concentration risk percentage |
|
|
|
2.56%
|
2.66%
|
| Interest Income | Credit Concentration Risk | Top Ten Advance Holders |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
100.00%
|
100.00%
|
100.00%
|
100.00%
|
100.00%
|
| Interest Income |
$ 930,289
|
$ 771,558
|
$ 2,422,273
|
$ 2,327,470
|
$ 3,006,293
|
| Interest Income | Credit Concentration Risk | Citibank, N.A. |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
33.14%
|
21.68%
|
23.53%
|
22.11%
|
20.86%
|
| Interest Income |
$ 308,253
|
$ 167,249
|
$ 570,185
|
$ 514,552
|
$ 627,210
|
| Interest Income | Credit Concentration Risk | MetLife, Inc.: |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
14.15%
|
17.56%
|
15.33%
|
17.05%
|
17.50%
|
| Interest Income |
$ 131,672
|
$ 135,432
|
$ 371,310
|
$ 396,714
|
$ 526,254
|
| Interest Income | Credit Concentration Risk | Metropolitan Life Insurance Company |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
12.76%
|
15.76%
|
13.76%
|
15.33%
|
15.72%
|
| Interest Income |
$ 118,731
|
$ 121,581
|
$ 333,342
|
$ 356,719
|
$ 472,618
|
| Interest Income | Credit Concentration Risk | Metropolitan Tower Life Insurance Company |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
1.39%
|
1.80%
|
1.57%
|
1.72%
|
1.78%
|
| Interest Income |
$ 12,941
|
$ 13,851
|
$ 37,968
|
$ 39,995
|
$ 53,636
|
| Interest Income | Credit Concentration Risk | Teachers Ins. and Annuity Assoc of America |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
14.43%
|
10.66%
|
15.48%
|
10.86%
|
10.98%
|
| Interest Income |
$ 134,205
|
$ 82,220
|
$ 374,977
|
$ 252,662
|
$ 330,216
|
| Interest Income | Credit Concentration Risk | Flagstar Bank, N.A. |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
8.87%
|
16.79%
|
10.37%
|
17.55%
|
17.47%
|
| Interest Income |
$ 82,471
|
$ 129,550
|
$ 251,097
|
$ 408,530
|
$ 525,013
|
| Interest Income | Credit Concentration Risk | Equitable Financial Life Insurance Co. |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
7.79%
|
9.51%
|
8.27%
|
9.34%
|
9.42%
|
| Interest Income |
$ 72,493
|
$ 73,383
|
$ 200,465
|
$ 217,384
|
$ 283,217
|
| Interest Income | Credit Concentration Risk | Manufacturers and Traders Trust Company |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
5.00%
|
|
7.11%
|
|
|
| Interest Income |
$ 46,518
|
|
$ 172,125
|
|
|
| Interest Income | Credit Concentration Risk | New York Life Insurance Company |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
5.38%
|
5.30%
|
6.05%
|
5.29%
|
5.53%
|
| Interest Income |
$ 50,052
|
$ 40,898
|
$ 146,605
|
$ 123,178
|
$ 166,103
|
| Interest Income | Credit Concentration Risk | Guardian Life Insurance Co. of America |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
4.13%
|
4.61%
|
4.54%
|
4.04%
|
4.26%
|
| Interest Income |
$ 38,436
|
$ 35,533
|
$ 109,853
|
$ 94,035
|
$ 128,077
|
| Interest Income | Credit Concentration Risk | Goldman Sachs Bank USA |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
4.53%
|
7.58%
|
6.21%
|
7.47%
|
7.49%
|
| Interest Income |
$ 42,147
|
$ 58,488
|
$ 150,380
|
$ 173,957
|
$ 225,157
|
| Interest Income | Credit Concentration Risk | ESL Federal Credit Union |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
2.58%
|
|
3.11%
|
|
|
| Interest Income |
$ 24,042
|
|
$ 75,276
|
|
|
| Interest Income | Credit Concentration Risk | Prudential Insurance Company of America |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
|
2.72%
|
|
2.68%
|
2.77%
|
| Interest Income |
|
$ 21,020
|
|
$ 62,376
|
$ 83,396
|
| Interest Income | Credit Concentration Risk | Valley National Bank |
|
|
|
|
|
| Concentration Risk [Line Items] |
|
|
|
|
|
| Concentration risk percentage |
|
3.60%
|
|
3.61%
|
3.71%
|
| Interest Income |
|
$ 27,785
|
|
$ 84,082
|
$ 111,650
|