CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating activities
Net income	$ 541,924	$ 383,583
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provisions for credit losses	28,871	131,841
Income tax expense	184,108	128,820
Amortization of brokered deposit placement fee	5,484	5,986
Amortization of Secured Borrowing Facility upfront fee	1,174	1,441
Amortization of deferred loan origination costs and loan premium/(discounts), net	6,260	6,402
Net amortization of discount on investments	(1,047)	(1,317)
Increase in tax indemnification receivable	0	(86)
Depreciation of premises and equipment	9,267	9,145
Acquired intangible assets amortization expense	2,609	4,517
Stock-based compensation expense	23,367	19,828
Unrealized (gains) losses on derivatives and hedging activities, net	43	(339)
Gains on sales of loans, net	(254,968)	(124,745)
Gains on securities, net	(4,221)	(498)
Other adjustments to net income, net	5,602	8,883
Changes in operating assets and liabilities:
Increase in accrued interest receivable	(550,931)	(511,089)
Increase in non-marketable securities	(283)	(691)
Decrease (increase) in other interest-earning assets	2,867	(790)
Increase in other assets	(23,389)	(37,573)
Decrease in income taxes payable, net	(163,936)	(74,596)
(Decrease) increase in accrued interest payable	(5,572)	10,433
Decrease in other liabilities	(27,742)	(17,301)
Total adjustments	(762,437)	(441,729)
Total net cash used in operating activities	(220,513)	(58,146)
Investing activities
Loans acquired and originated	(3,291,778)	(3,132,075)
Net proceeds from sales of loans held for investment and loans held for sale	3,761,722	2,157,028
Proceeds from FFELP Loan claim payments	20,034	26,477
Net decrease in loans held for investment and loans held for sale (other than loans acquired and originated, and loan sales)	1,380,714	1,605,292
Purchases of available-for-sale securities	(60,012)	(44,782)
Proceeds from sales and maturities of available-for-sale securities	410,835	148,092
Total net cash provided by investing activities	2,221,515	760,032
Financing activities
Brokered deposit placement fee	0	(2,634)
Net decrease in certificates of deposit	(175,483)	(303,027)
Net decrease in other deposits	(744,832)	(793,068)
Borrowings collateralized by loans in securitization trusts - issued	665,069	569,513
Borrowings collateralized by loans in securitization trusts - repaid	(494,161)	(596,692)
Issuance costs for unsecured debt offering	0	(15)
Fees paid on Secured Borrowing Facility	(2,333)	(2,850)
Common stock dividends paid	(48,305)	(51,938)
Preferred stock dividends paid	(9,281)	(8,337)
Common stock repurchased	(86,505)	(259,331)
Total net cash used in financing activities	(895,831)	(1,448,379)
Net decrease in cash, cash equivalents and restricted cash	1,105,171	(746,493)
Cash, cash equivalents and restricted cash at beginning of period	4,299,507	4,772,836
Cash, cash equivalents and restricted cash at end of period	5,404,678	4,026,343
Cash disbursements made for:
Interest	535,146	449,268
Income taxes paid	164,710	82,307
Income taxes refunded	(1,251)	(8,157)
Reconciliation of the Consolidated Statements of Cash Flows to the Consolidated Balance Sheets:
Cash and cash equivalents	5,262,448	3,875,758
Restricted cash	142,230	150,585
Total cash, cash equivalents and restricted cash	$ 5,404,678	$ 4,026,343