CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating activities
Net income	$ 546,057,000	$ 854,248,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provisions for credit losses	336,193,000	(17,648,000)
Income tax expense	181,203,000	276,091,000
Amortization of brokered deposit placement fee	9,757,000	11,932,000
Amortization of Secured Borrowing Facility upfront fee	1,930,000	1,845,000
Amortization of deferred loan origination costs and loan premium/(discounts), net	11,619,000	11,851,000
Net amortization of discount on investments	802,000	5,902,000
(Increase) reduction in tax indemnification receivable	(345,000)	6,006,000
Depreciation of premises and equipment	12,840,000	11,445,000
Acquired intangible assets amortization expense	5,478,000	0
Stock-based compensation expense	27,152,000	24,254,000
Unrealized (gains) losses on derivatives and hedging activities, net	247,000	21,434,000
Gains on sales of loans, net	(324,856,000)	(402,780,000)
Acquisition transaction costs, net	2,602,000	0
Other adjustments to net income, net	13,174,000	(29,229,000)
Changes in operating assets and liabilities:
Increase in accrued interest receivable	(580,704,000)	(556,143,000)
Increase in trading investments	(5,064,000)	0
Increase in non-marketable securities	(2,050,000)	(9,415,000)
(Increase) decrease in other interest-earning assets	(1,370,000)	30,983,000
Decrease (increase) in other assets	(20,725,000)	(110,841,000)
Decrease in income taxes payable, net	(217,909,000)	(230,072,000)
Increase in accrued interest payable	25,307,000	4,153,000
(Decrease) increase in other liabilities	(15,471,000)	860,000
Total adjustments	(540,190,000)	(949,372,000)
Total net cash provided by (used in) operating activities	5,867,000	(95,124,000)
Investing activities
Loans acquired and originated	(5,234,895,000)	(4,744,212,000)
Net proceeds from sales of loans held for investment	3,460,758,000	3,436,075,000
Proceeds from FFELP Loan claim payments	22,587,000	14,653,000
Net decrease in loans held for investment (other than loan sales)	2,833,822,000	2,835,850,000
Purchases of available-for-sale securities	(753,129,000)	(1,159,667,000)
Proceeds from sales and maturities of available-for-sale securities	812,712,000	799,193,000
Purchase of subsidiary, net of cash acquired	(127,654,000)	0
Total net cash provided by investing activities	1,014,201,000	1,181,892,000
Financing activities
Brokered deposit placement fee	(8,147,000)	(11,182,000)
Net decrease in certificates of deposit	(77,938,000)	(1,690,990,000)
Net increase (decrease) in other deposits	611,851,000	(12,172,000)
Borrowings collateralized by loans in securitization trusts - issued	572,640,000	1,053,633,000
Cash, cash equivalents and restricted cash at end of period	5,024,671,000	2,893,225,000
Borrowings collateralized by loans in securitization trusts - repaid	(988,505,000)	(830,026,000)
Fees paid on Secured Borrowing Facility	(2,838,000)	(2,846,000)
Common stock dividends paid	(86,219,000)	(29,104,000)
Preferred stock dividends paid	(5,563,000)	(3,559,000)
Common stock repurchased	(555,607,000)	(1,276,681,000)
Total net cash used in financing activities	(540,741,000)	(2,803,252,000)
Net increase (decrease) in cash, cash equivalents and restricted cash	479,327,000	(1,716,484,000)
Cash, cash equivalents and restricted cash at beginning of period	4,545,344,000	4,609,709,000
Cash disbursements made for:
Interest	285,626,000	261,205,000
Income taxes paid	219,975,000	237,882,000
Income taxes refunded	(2,023,000)	(7,610,000)
Reconciliation of the Consolidated Statements of Cash Flows to the Consolidated Balance Sheets:
Cash and cash equivalents	4,846,754,000	2,717,752,000
Restricted cash	177,917,000	175,473,000
Total cash, cash equivalents and restricted cash	5,024,671,000	2,893,225,000
Collateralized Securities
Financing activities
Issuance costs for collateralized borrowings	(40,000)	0
Issuance costs for unsecured debt offering	(40,000)	0
Unsecured borrowings
Financing activities
Issuance costs for collateralized borrowings	(375,000)	(325,000)
Issuance costs for unsecured debt offering	$ (375,000)	$ (325,000)