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Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Details) - USD ($) $ in Thousands | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Earning assets: |  |
Trading investments | $ 58,166 | $ 54,481
Accrued interest receivable, difference | 80,762 | 68,862
Tax indemnification receivable | 277,733 | 366,247
Derivative instruments | 125 | 0
Total earning assets, difference | 2,743,938 | 2,534,325
Interest-bearing liabilities: |  |
Long-term borrowings, difference | 273,686 | 353,822
Derivative instruments | 33 | 370
Total interest-bearing liabilities, difference | 474,975 | 489,912
Excess of net asset fair value over carrying value | 3,218,913 | 3,024,237
Money-market and savings accounts |  |
Interest-bearing liabilities: |  |
Deposits, difference | 149,051 | 68,409
Certificates of deposit |  |
Interest-bearing liabilities: |  |
Deposits, difference | 52,238 | 67,681
Fair Value |  |
Earning assets: |  |
Cash and cash equivalents | 3,584,013 | 4,149,838
Trading investments | 58,166 | 54,481
Available-for-sale investments | 2,271,108 | 2,411,622
Accrued interest receivable | 1,467,249 | 1,448,766
Tax indemnification receivable | 0 | 0
Derivative instruments | 208 | 0
Total earning assets | 30,244,709 | 30,836,527
Interest-bearing liabilities: |  |
Long-term borrowings | 4,703,196 | 4,873,690
Accrued interest payable | 89,328 | 105,066
Derivative instruments | 116 | 370
Total interest-bearing liabilities | 25,492,560 | 26,494,693
Fair Value | Money-market and savings accounts |  |
Interest-bearing liabilities: |  |
Deposits | 10,268,578 | 11,134,883
Fair Value | Certificates of deposit |  |
Interest-bearing liabilities: |  |
Deposits | 10,431,342 | 10,380,684
Carrying Value |  |
Earning assets: |  |
Cash and cash equivalents | 3,584,013 | 4,149,838
Trading investments | 58,166 | 54,481
Available-for-sale investments | 2,271,108 | 2,411,622
Accrued interest receivable | 1,386,487 | 1,379,904
Tax indemnification receivable | 0 | 0
Derivative instruments | 208 | 0
Total earning assets | 27,500,771 | 28,302,202
Interest-bearing liabilities: |  |
Long-term borrowings | 4,976,882 | 5,227,512
Accrued interest payable | 89,328 | 105,066
Derivative instruments | 116 | 370
Total interest-bearing liabilities | 25,967,535 | 26,984,605
Carrying Value | Money-market and savings accounts |  |
Interest-bearing liabilities: |  |
Deposits | 10,417,629 | 11,203,292
Carrying Value | Certificates of deposit |  |
Interest-bearing liabilities: |  |
Deposits | 10,483,580 | 10,448,365
Private Education Loans |  |
Earning assets: |  |
Loans held for investment, net, difference | 2,654,655 | 2,456,752
Private Education Loans | Fair Value |  |
Earning assets: |  |
Loans held for investment, net | 22,342,438 | 22,229,045
Private Education Loans | Carrying Value |  |
Earning assets: |  |
Loans held for investment, net | 19,687,783 | 19,772,293
FFELP Loans |  |
Earning assets: |  |
Loans held for investment, net, difference | 8,521 | 8,711
FFELP Loans | Fair Value |  |
Earning assets: |  |
Loans held for investment, net | 521,527 | 542,775
FFELP Loans | Carrying Value |  |
Earning assets: |  |
Loans held for investment, net | $ 513,006 | $ 534,064

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- Definition Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities. + References No definition available. + Details
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