v3.26.1
Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Assets      
Investments in available-for-sale securities, fair value $ 3,048,360   $ 2,454,453
Investment securities 3,231,227   2,575,607
Servicing rights 367,902   378,178
Liabilities      
Residual interests classified as debt 517   520
Fair Value      
Assets      
Total assets 5,459,457   7,173,368
Liabilities      
Debt 2,501,705   3,483,347
Total liabilities 42,744,625   40,990,036
U.S. Treasury securities      
Assets      
Investments in available-for-sale securities, fair value 221,588   75,356
Agency mortgage-backed securities      
Assets      
Investments in available-for-sale securities, fair value 2,806,412   2,354,606
Corporate bonds      
Assets      
Investments in available-for-sale securities, fair value 184   185
Other      
Assets      
Investments in available-for-sale securities, fair value 825   833
Asset-backed bonds      
Assets      
Investments in available-for-sale securities, fair value 15,925   19,703
Residual investments      
Assets      
Investments in available-for-sale securities, fair value 3,426   3,770
Fair Value, Recurring      
Liabilities      
Unpaid principal related to debt measured at fair value 53,081   56,255
Gains (losses) from changes in fair value in debt 0 $ (760)  
Fair Value, Recurring | Fair Value      
Assets      
Investment securities 3,231,227   2,575,607
Loans at fair value 40,667,249   36,403,361
Servicing rights 367,902   378,178
Total assets 44,458,065   39,458,019
Liabilities      
Debt 50,891   54,107
Residual interests classified as debt 517   520
Derivative liabilities 1,506   4,680
Total liabilities 52,914   59,307
Fair Value, Recurring | Fair Value | Third party warrants      
Assets      
Derivative assets 540   540
Fair Value, Recurring | Fair Value | Derivative assets      
Assets      
Derivative assets 155,282   61,583
Fair Value, Recurring | Fair Value | IRLCs      
Assets      
Derivative assets 7,561   9,971
Fair Value, Recurring | U.S. Treasury securities | Fair Value      
Assets      
Investments in available-for-sale securities, fair value 221,588   75,356
Fair Value, Recurring | Agency mortgage-backed securities | Fair Value      
Assets      
Investments in available-for-sale securities, fair value 2,806,412   2,354,606
Fair Value, Recurring | Corporate bonds | Fair Value      
Assets      
Investments in available-for-sale securities, fair value 184   185
Fair Value, Recurring | Other | Fair Value      
Assets      
Investments in available-for-sale securities, fair value 825   833
Fair Value, Recurring | Asset-backed bonds | Fair Value      
Assets      
Asset-backed bonds and residual investments 164,601   113,272
Fair Value, Recurring | Residual investments | Fair Value      
Assets      
Asset-backed bonds and residual investments 37,617   31,355
Fair Value, Recurring | Student loan commitments | Fair Value      
Assets      
Student loan commitments 19,270   28,779
Fair Value, Recurring | Personal loan commitments | Fair Value      
Assets      
Student loan commitments 9,034   0
Level 1      
Assets      
Total assets 3,761,251   5,356,773
Liabilities      
Debt 2,015,705   2,997,347
Total liabilities 2,015,705   2,997,347
Level 1 | Fair Value, Recurring      
Assets      
Investment securities 221,588   75,356
Loans at fair value 0   0
Servicing rights 0   0
Total assets 221,588   75,356
Liabilities      
Debt 0   0
Residual interests classified as debt 0   0
Derivative liabilities 0   0
Total liabilities 0   0
Level 1 | Fair Value, Recurring | Third party warrants      
Assets      
Derivative assets 0   0
Level 1 | Fair Value, Recurring | Derivative assets      
Assets      
Derivative assets 0   0
Level 1 | Fair Value, Recurring | IRLCs      
Assets      
Derivative assets 0   0
Level 1 | Fair Value, Recurring | U.S. Treasury securities      
Assets      
Investments in available-for-sale securities, fair value 221,588   75,356
Level 1 | Fair Value, Recurring | Agency mortgage-backed securities      
Assets      
Investments in available-for-sale securities, fair value 0   0
Level 1 | Fair Value, Recurring | Corporate bonds      
Assets      
Investments in available-for-sale securities, fair value 0   0
Level 1 | Fair Value, Recurring | Other      
Assets      
Investments in available-for-sale securities, fair value 0   0
Level 1 | Fair Value, Recurring | Asset-backed bonds      
Assets      
Asset-backed bonds and residual investments 0   0
Level 1 | Fair Value, Recurring | Residual investments      
Assets      
Asset-backed bonds and residual investments 0   0
Level 1 | Fair Value, Recurring | Student loan commitments      
Assets      
Student loan commitments 0   0
Level 1 | Fair Value, Recurring | Personal loan commitments      
Assets      
Student loan commitments 0   0
Level 2      
Assets      
Total assets 146,503   146,204
Liabilities      
Debt 486,000   486,000
Total liabilities 40,728,920   37,992,689
Level 2 | Fair Value, Recurring      
Assets      
Investment securities 2,972,022   2,468,896
Loans at fair value 325,029   204,133
Servicing rights 0   0
Total assets 3,452,333   2,734,612
Liabilities      
Debt 50,891   54,107
Residual interests classified as debt 0   0
Derivative liabilities 1,506   4,680
Total liabilities 52,397   58,787
Level 2 | Fair Value, Recurring | Third party warrants      
Assets      
Derivative assets 0   0
Level 2 | Fair Value, Recurring | Derivative assets      
Assets      
Derivative assets 155,282   61,583
Level 2 | Fair Value, Recurring | IRLCs      
Assets      
Derivative assets 0   0
Level 2 | Fair Value, Recurring | U.S. Treasury securities      
Assets      
Investments in available-for-sale securities, fair value 0   0
Level 2 | Fair Value, Recurring | Agency mortgage-backed securities      
Assets      
Investments in available-for-sale securities, fair value 2,806,412   2,354,606
Level 2 | Fair Value, Recurring | Corporate bonds      
Assets      
Investments in available-for-sale securities, fair value 184   185
Level 2 | Fair Value, Recurring | Other      
Assets      
Investments in available-for-sale securities, fair value 825   833
Level 2 | Fair Value, Recurring | Asset-backed bonds      
Assets      
Asset-backed bonds and residual investments 164,601   113,272
Level 2 | Fair Value, Recurring | Residual investments      
Assets      
Asset-backed bonds and residual investments 0   0
Level 2 | Fair Value, Recurring | Student loan commitments      
Assets      
Student loan commitments 0   0
Level 2 | Fair Value, Recurring | Personal loan commitments      
Assets      
Student loan commitments 0   0
Level 3      
Assets      
Total assets 1,551,703   1,670,391
Liabilities      
Debt 0   0
Total liabilities 0   0
Level 3 | Fair Value, Recurring      
Assets      
Investment securities 37,617   31,355
Loans at fair value 40,342,220   36,199,228
Servicing rights 367,902   378,178
Total assets 40,784,144   36,648,051
Liabilities      
Debt 0   0
Residual interests classified as debt 517   520
Derivative liabilities 0   0
Total liabilities 517   520
Level 3 | Fair Value, Recurring | Third party warrants      
Assets      
Derivative assets 540   540
Level 3 | Fair Value, Recurring | Derivative assets      
Assets      
Derivative assets 0   0
Level 3 | Fair Value, Recurring | IRLCs      
Assets      
Derivative assets 7,561   9,971
Level 3 | Fair Value, Recurring | U.S. Treasury securities      
Assets      
Investments in available-for-sale securities, fair value 0   0
Level 3 | Fair Value, Recurring | Agency mortgage-backed securities      
Assets      
Investments in available-for-sale securities, fair value 0   0
Level 3 | Fair Value, Recurring | Corporate bonds      
Assets      
Investments in available-for-sale securities, fair value 0   0
Level 3 | Fair Value, Recurring | Other      
Assets      
Investments in available-for-sale securities, fair value 0   0
Level 3 | Fair Value, Recurring | Asset-backed bonds      
Assets      
Asset-backed bonds and residual investments 0   0
Level 3 | Fair Value, Recurring | Residual investments      
Assets      
Asset-backed bonds and residual investments 37,617   31,355
Level 3 | Fair Value, Recurring | Student loan commitments      
Assets      
Student loan commitments 19,270   28,779
Level 3 | Fair Value, Recurring | Personal loan commitments      
Assets      
Student loan commitments $ 9,034   $ 0