CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities
Net income	$ 412,948	$ 546,057
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provisions for credit losses	329,864	336,193
Income tax expense	140,062	181,203
Amortization of brokered deposit placement fee	8,818	9,757
Amortization of Secured Borrowing Facility upfront fee	2,149	1,930
Amortization of deferred loan origination costs and loan premium/(discounts), net	9,831	11,619
Net amortization of discount on investments	(2,012)	802
Increase in tax indemnification receivable	(129)	(345)
Depreciation of premises and equipment	13,404	12,840
Acquired intangible assets amortization expense	7,351	5,478
Stock-based compensation expense	28,300	27,152
Unrealized (gains) losses on derivatives and hedging activities, net	(280)	247
Gains on sales of loans, net	(124,740)	(324,856)
(Gains) losses on securities, net	(1,988)	2,021
Acquisition transaction costs, net	997	2,602
Other adjustments to net income, net	12,279	11,153
Changes in operating assets and liabilities:
Increase in accrued interest receivable	(777,125)	(580,704)
Increase in trading investments	0	(5,064)
Increase in non-marketable securities	(853)	(2,050)
Decrease (increase) in other interest-earning assets	75	(1,370)
Increase in other assets	(31,211)	(20,725)
Decrease in income taxes payable, net	(163,077)	(217,909)
Increase in accrued interest payable	27,829	25,307
Decrease in other liabilities	(9,988)	(15,471)
Total adjustments	(530,444)	(540,190)
Total net cash (used in) provided by operating activities	(117,496)	5,867
Investing activities
Loans acquired and originated	(5,600,123)	(5,234,895)
Net proceeds from sales of loans held for investment and loans held for sale	2,157,024	3,460,758
Proceeds from FFELP Loan claim payments	39,836	22,587
Net decrease in loans held for investment and loans held for sale (other than loans acquired and originated, and loan sales)	2,338,426	2,833,822
Purchases of available-for-sale securities	(70,790)	(753,129)
Proceeds from sales and maturities of available-for-sale securities	215,042	812,712
Purchase of subsidiary, net of cash acquired	(14,654)	(127,654)
Total net cash (used in) provided by investing activities	(935,239)	1,014,201
Financing activities
Brokered deposit placement fee	(6,904)	(8,147)
Net increase (decrease) in certificates of deposit	886,475	(77,938)
Net increase (decrease) in other deposits	(796,218)	611,851
Borrowings collateralized by loans in securitization trusts - issued	1,135,054	572,640
Borrowings collateralized by loans in securitization trusts - repaid	(863,230)	(988,505)
Fees paid on Secured Borrowing Facility	(2,850)	(2,838)
Common stock dividends paid	(76,817)	(86,219)
Preferred stock dividends paid	(12,979)	(5,563)
Common stock repurchased	(259,331)	(555,607)
Total net cash provided by (used in) financing activities	3,185	(540,741)
Net increase (decrease) in cash, cash equivalents and restricted cash	(1,049,550)	479,327
Cash, cash equivalents and restricted cash at beginning of period	4,772,836	4,545,344
Cash, cash equivalents and restricted cash at end of period	3,723,286	5,024,671
Cash disbursements made for:
Interest	691,632	285,626
Income taxes paid	171,022	219,975
Income taxes refunded	(8,157)	(2,023)
Reconciliation of the Consolidated Statements of Cash Flows to the Consolidated Balance Sheets:
Cash and cash equivalents	3,548,225	4,846,754
Restricted cash	175,061	177,917
Total cash, cash equivalents and restricted cash	3,723,286	5,024,671
Collateralized borrowings
Financing activities
Issuance costs	(15)	(40)
Unsecured debt offering
Financing activities
Issuance costs	$ 0	$ (375)