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Allowance for Credit Losses - Loan Portfolio Stratified by Key Credit Quality Indicators (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
% of Balance |  |  |
Current period recoveries, total | $ (421,096) | $ (431,244) | $ (230,268)
Current period recoveries, total | 46,368 | 41,742 | 29,506
Current period net charge-offs, total | (374,728) | (389,502) | (200,762)
Consumer Portfolio Segment | Student Loan |  |  |
% of Balance |  |  |
Current period gross charge-offs, Year 1 | (1,812) | (2,224) |
Current period gross charge-offs, Year 2 | (31,032) | (25,698) |
Current period gross charge-offs, Year 3 | (70,331) | (48,271) |
Current period gross charge-offs, Year 4 | (49,624) | (62,071) |
Current period gross charge-offs, Year 5 | (50,585) | (57,505) |
Current period gross charge-offs, Year 6 | (216,711) | (231,647) |
Current period recoveries, total | (420,095) | (427,416) |
Current period recoveries, Year 1 | 172 | 124 |
Current period recoveries, Year 2 | 2,342 | 1,841 |
Current period recoveries, Year 3 | 6,496 | 4,170 |
Current period recoveries, Year 4 | 4,923 | 5,556 |
Current period recoveries, Year 5 | 5,260 | 5,407 |
Current period recoveries, Year 6 | 27,175 | 24,639 |
Current period recoveries, total | 46,368 | 41,737 |
Current period net charge-offs, Year 1 | (1,640) | (2,100) |
Current period net charge-offs, Year 2 | (28,690) | (23,857) |
Current period net charge-offs, Year 3 | (63,835) | (44,101) |
Current period net charge-offs, Year 4 | (44,701) | (56,515) |
Current period net charge-offs, Year 5 | (45,325) | (52,098) |
Current period net charge-offs, Year 6 | (189,536) | (207,008) |
Current period net charge-offs, total | (373,727) | (385,679) |
Total accrued interest by origination vintage, Year 1 | 177,959 | 142,915 |
Total accrued interest by origination vintage, Year 2 | 408,800 | 315,308 |
Total accrued interest by origination vintage, Year 3 | 269,978 | 207,858 |
Total accrued interest by origination vintage, Year 4 | 152,094 | 184,832 |
Total accrued interest by origination vintage, Year 5 | 116,618 | 116,211 |
Total accrued interest by origination vintage, Year 6 | 229,116 | 210,438 |
Total accrued interest by origination vintage | 1,354,565 | 1,177,562 |
Consumer Portfolio Segment | Student Loan | Loan delinquent, current |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | 2,469,817 | 2,411,441 | 2,234,876
Year 2 | 3,254,534 | 2,991,839 | 2,786,646
Year 3 | 2,131,040 | 1,907,574 | 2,321,728
Year 4 | 1,416,069 | 1,683,986 | 1,772,651
Year 5 | 1,323,825 | 1,301,809 | 1,570,815
After Year 5 | 4,213,986 | 4,262,698 | 4,319,057
Loan type | 14,809,271 | 14,559,347 | 15,005,773
Consumer Portfolio Segment | Student Loan | Loan delinquent 30-59 days |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | 17,599 | 14,164 | 15,148
Year 2 | 34,627 | 30,740 | 29,146
Year 3 | 37,147 | 30,877 | 46,616
Year 4 | 28,020 | 35,213 | 43,197
Year 5 | 31,432 | 31,366 | 41,695
After Year 5 | 149,926 | 144,948 | 132,757
Loan type | 298,751 | 287,308 | 308,559
Consumer Portfolio Segment | Student Loan | Loan delinquent 60-89 days |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | 5,720 | 5,523 | 3,194
Year 2 | 17,227 | 15,056 | 7,441
Year 3 | 20,077 | 14,433 | 14,044
Year 4 | 16,614 | 18,201 | 14,310
Year 5 | 15,482 | 16,697 | 16,425
After Year 5 | 75,897 | 77,595 | 61,533
Loan type | 151,017 | 147,505 | 116,947
Consumer Portfolio Segment | Student Loan | Loan delinquent 90 days or greater past due |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | 1,678 | 1,710 | 642
Year 2 | 16,939 | 11,842 | 3,683
Year 3 | 21,470 | 14,872 | 8,453
Year 4 | 15,155 | 16,819 | 10,632
Year 5 | 16,150 | 16,107 | 11,935
After Year 5 | 79,383 | 74,040 | 44,588
Loan type | 150,775 | 135,390 | $ 79,933
Consumer Portfolio Segment | Student Loan | With and without cosigners |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | 4,490,119 | 4,276,533 |
Year 2 | 5,088,739 | 4,547,159 |
Year 3 | 2,937,422 | 2,584,622 |
Year 4 | 1,819,089 | 2,172,660 |
Year 5 | 1,632,300 | 1,615,842 |
After Year 5 | 5,058,175 | 5,106,872 |
Loan type | $ 21,025,844 | $ 20,303,688 |
% of Balance |  |  |
Total in percent | 100.00% | 100.00% |
Consumer Portfolio Segment | Student Loan | With cosigner |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 3,903,676 | $ 3,656,111 |
Year 2 | 4,428,163 | 3,941,921 |
Year 3 | 2,516,380 | 2,208,033 |
Year 4 | 1,535,308 | 1,853,619 |
Year 5 | 1,378,699 | 1,402,828 |
After Year 5 | 4,529,768 | 4,626,491 |
Loan type | $ 18,291,994 | $ 17,689,003 |
% of Balance |  |  |
Private education loans | 87.00% | 87.00% |
Consumer Portfolio Segment | Student Loan | Without cosigner |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 586,443 | $ 620,422 |
Year 2 | 660,576 | 605,238 |
Year 3 | 421,042 | 376,589 |
Year 4 | 283,781 | 319,041 |
Year 5 | 253,601 | 213,014 |
After Year 5 | 528,407 | 480,381 |
Loan type | $ 2,733,850 | $ 2,614,685 |
% of Balance |  |  |
Private education loans | 13.00% | 13.00% |
Consumer Portfolio Segment | Student Loan | FICO at Origination |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 4,490,119 | $ 4,276,533 |
Year 2 | 5,088,739 | 4,547,159 |
Year 3 | 2,937,422 | 2,584,622 |
Year 4 | 1,819,089 | 2,172,660 |
Year 5 | 1,632,300 | 1,615,842 |
After Year 5 | 5,058,175 | 5,106,872 |
Loan type | $ 21,025,844 | $ 20,303,688 |
% of Balance |  |  |
Total in percent | 100.00% | 100.00% |
Consumer Portfolio Segment | Student Loan | FICO at Origination | Less than 670 |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 328,199 | $ 326,991 |
Year 2 | 395,526 | 307,646 |
Year 3 | 208,696 | 158,606 |
Year 4 | 118,935 | 177,098 |
Year 5 | 137,494 | 143,674 |
After Year 5 | 451,613 | 439,587 |
Loan type | $ 1,640,463 | $ 1,553,602 |
% of Balance |  |  |
Private Education Loans at origination | 8.00% | 8.00% |
Consumer Portfolio Segment | Student Loan | FICO at Origination | 670-699 |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 635,642 | $ 593,216 |
Year 2 | 704,642 | 611,649 |
Year 3 | 400,744 | 356,541 |
Year 4 | 254,762 | 339,685 |
Year 5 | 257,840 | 259,142 |
After Year 5 | 868,777 | 878,426 |
Loan type | $ 3,122,407 | $ 3,038,659 |
% of Balance |  |  |
Private Education Loans at origination | 15.00% | 15.00% |
Consumer Portfolio Segment | Student Loan | FICO at Origination | 700-749 |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 1,383,779 | $ 1,336,765 |
Year 2 | 1,586,783 | 1,440,510 |
Year 3 | 934,033 | 834,819 |
Year 4 | 590,401 | 719,777 |
Year 5 | 545,333 | 537,680 |
After Year 5 | 1,709,299 | 1,722,068 |
Loan type | $ 6,749,628 | $ 6,591,619 |
% of Balance |  |  |
Private Education Loans at origination | 32.00% | 32.00% |
Consumer Portfolio Segment | Student Loan | FICO at Origination | Greater than or equal to 750 |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 2,142,499 | $ 2,019,561 |
Year 2 | 2,401,788 | 2,187,354 |
Year 3 | 1,393,949 | 1,234,656 |
Year 4 | 854,991 | 936,100 |
Year 5 | 691,633 | 675,346 |
After Year 5 | 2,028,486 | 2,066,791 |
Loan type | $ 9,513,346 | $ 9,119,808 |
% of Balance |  |  |
Private Education Loans at origination | 45.00% | 45.00% |
Consumer Portfolio Segment | Student Loan | FICO Refreshed |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 4,490,119 | $ 4,276,533 |
Year 2 | 5,088,739 | 4,547,159 |
Year 3 | 2,937,422 | 2,584,622 |
Year 4 | 1,819,089 | 2,172,660 |
Year 5 | 1,632,300 | 1,615,842 |
After Year 5 | 5,058,175 | 5,106,872 |
Loan type | $ 21,025,844 | $ 20,303,688 |
% of Balance |  |  |
Total in percent | 100.00% | 100.00% |
Consumer Portfolio Segment | Student Loan | FICO Refreshed | Less than 670 |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 495,451 | $ 443,868 |
Year 2 | 638,381 | 461,589 |
Year 3 | 379,738 | 242,310 |
Year 4 | 217,956 | 237,105 |
Year 5 | 214,665 | 204,894 |
After Year 5 | 791,875 | 773,324 |
Loan type | $ 2,738,066 | $ 2,363,090 |
% of Balance |  |  |
Private Education Loans at origination | 13.00% | 12.00% |
Consumer Portfolio Segment | Student Loan | FICO Refreshed | 670-699 |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 616,684 | $ 594,118 |
Year 2 | 672,777 | 579,784 |
Year 3 | 365,674 | 284,244 |
Year 4 | 193,462 | 240,999 |
Year 5 | 176,963 | 173,754 |
After Year 5 | 564,245 | 564,344 |
Loan type | $ 2,589,805 | $ 2,437,243 |
% of Balance |  |  |
Private Education Loans at origination | 12.00% | 12.00% |
Consumer Portfolio Segment | Student Loan | FICO Refreshed | 700-749 |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 1,347,094 | $ 1,322,558 |
Year 2 | 1,477,310 | 1,378,910 |
Year 3 | 836,747 | 748,368 |
Year 4 | 498,414 | 628,060 |
Year 5 | 445,244 | 449,701 |
After Year 5 | 1,361,073 | 1,388,090 |
Loan type | $ 5,965,882 | $ 5,915,687 |
% of Balance |  |  |
Private Education Loans at origination | 28.00% | 29.00% |
Consumer Portfolio Segment | Student Loan | FICO Refreshed | Greater than or equal to 750 |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 2,030,890 | $ 1,915,989 |
Year 2 | 2,300,271 | 2,126,876 |
Year 3 | 1,355,263 | 1,309,700 |
Year 4 | 909,257 | 1,066,496 |
Year 5 | 795,428 | 787,493 |
After Year 5 | 2,340,982 | 2,381,114 |
Loan type | $ 9,732,091 | $ 9,587,668 |
% of Balance |  |  |
Private Education Loans at origination | 47.00% | 47.00% |
Consumer Portfolio Segment | Student Loan | Seasoning |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 4,490,119 | $ 4,276,533 |
Year 2 | 5,088,739 | 4,547,159 |
Year 3 | 2,937,422 | 2,584,622 |
Year 4 | 1,819,089 | 2,172,660 |
Year 5 | 1,632,300 | 1,615,842 |
After Year 5 | 5,058,175 | 5,106,872 |
Loan type | $ 21,025,844 | $ 20,303,688 |
% of Balance |  |  |
Total in percent | 100.00% | 100.00% |
Consumer Portfolio Segment | Student Loan | Seasoning | 1-12 payments |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 2,514,079 | $ 2,448,884 |
Year 2 | 740,450 | 636,073 |
Year 3 | 440,293 | 384,334 |
Year 4 | 245,631 | 330,316 |
Year 5 | 208,941 | 235,878 |
After Year 5 | 332,608 | 424,636 |
Loan type | $ 4,482,002 | $ 4,460,121 |
% of Balance |  |  |
Seasoning based on monthly scheduled payments due from 1-12 payments | 21.00% | 22.00% |
Consumer Portfolio Segment | Student Loan | Seasoning | 13-24 payments |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 0 | $ 0 |
Year 2 | 2,675,956 | 2,477,764 |
Year 3 | 303,045 | 255,510 |
Year 4 | 167,532 | 195,753 |
Year 5 | 165,577 | 166,045 |
After Year 5 | 384,760 | 455,782 |
Loan type | $ 3,696,870 | $ 3,550,854 |
% of Balance |  |  |
Seasoning based on monthly scheduled payments due from 13 - 24 payments | 18.00% | 18.00% |
Consumer Portfolio Segment | Student Loan | Seasoning | 25-36 payments |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 0 | $ 0 |
Year 2 | 0 | 0 |
Year 3 | 1,524,834 | 1,366,398 |
Year 4 | 195,091 | 257,534 |
Year 5 | 129,571 | 126,223 |
After Year 5 | 456,448 | 489,157 |
Loan type | $ 2,305,944 | $ 2,239,312 |
% of Balance |  |  |
Seasoning based on monthly scheduled payments due from 25 - 36 payments | 11.00% | 11.00% |
Consumer Portfolio Segment | Student Loan | Seasoning | 37-48 payments |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 0 | $ 0 |
Year 2 | 0 | 0 |
Year 3 | 0 | 127 |
Year 4 | 902,938 | 1,008,418 |
Year 5 | 208,521 | 224,805 |
After Year 5 | 446,350 | 451,102 |
Loan type | $ 1,557,809 | $ 1,684,452 |
% of Balance |  |  |
Seasoning based on monthly scheduled payments due from 37 - 48 payments | 7.00% | 8.00% |
Consumer Portfolio Segment | Student Loan | Seasoning | More than 48 payments |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 0 | $ 0 |
Year 2 | 0 | 0 |
Year 3 | 0 | 0 |
Year 4 | 116 | 0 |
Year 5 | 706,097 | 643,611 |
After Year 5 | 2,985,015 | 2,830,285 |
Loan type | $ 3,691,228 | $ 3,473,896 |
% of Balance |  |  |
Seasoning based on monthly scheduled payments due from more than 48 payments | 18.00% | 17.00% |
Consumer Portfolio Segment | Student Loan | Seasoning | Not yet in repayment |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Year 1 | $ 1,976,040 | $ 1,827,649 |
Year 2 | 1,672,333 | 1,433,322 |
Year 3 | 669,250 | 578,253 |
Year 4 | 307,781 | 380,639 |
Year 5 | 213,593 | 219,280 |
After Year 5 | 452,994 | 455,910 |
Loan type | $ 5,291,991 | $ 4,895,053 |
% of Balance |  |  |
Seasoning based on monthly scheduled payments due from not yet in repayment | 25.00% | 24.00% |

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