CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net income	$ 578,276	$ 487,476	$ 288,934
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Provisions for credit losses	354,249	244,864	185,765
Deferred tax benefit	(9,714)	(63,301)	(58,752)
Amortization of brokered deposit placement fee	17,788	13,055	9,372
Amortization of Secured Borrowing Facility upfront fee	1,117	1,128	1,316
Amortization of deferred loan origination costs and loan premium/(discounts), net	13,049	10,905	8,258
Net amortization of discount on investments	2,069	1,712	2,082
Reduction of tax indemnification receivable	11,649	92,815	31,888
Depreciation of premises and equipment	14,669	13,829	11,171
Stock-based compensation expense	30,600	31,524	27,899
Unrealized (gains) losses on derivative and hedging activities, net	(19,046)	(1,353)	7,248
Gains on sale of loans, net	0	(2,060)	0
Losses on sales of securities, net	0	1,549	0
Other adjustments to net income, net	3,724	7,446	6,305
Changes in operating assets and liabilities:
Increase in accrued interest receivable	(963,885)	(864,461)	(703,081)
Increase in non-marketable securities	(10,700)	(5,000)	0
(Increase) decrease in other interest-earning assets	(25,407)	(5,571)	27,528
Decrease in tax indemnification receivable	0	35,989	59,633
Increase in other assets	(3,091)	(64,777)	(72,646)
Decrease in income tax payable, net	(30,191)	(79,693)	(19,687)
Increase in accrued interest payable	13,817	25,979	14,304
Increase in other liabilities	5,386	15,204	1,304
Total adjustments	(593,917)	(590,217)	(460,093)
Total net cash used in operating activities	(15,641)	(102,741)	(171,159)
Investing activities
Loans acquired and originated	(6,138,105)	(6,493,367)	(5,243,732)
Net proceeds from sales of loans held for investment	0	44,832	6,992
Proceeds from claim payments	42,869	54,659	49,146
Net decrease in loans held for investment	4,094,021	3,076,992	2,065,727
Purchases of available-for-sale securities	(356,414)	(15,876)	(78,327)
Proceeds from sales and maturities of available-for-sale securities	50,915	77,897	40,044
Total net cash used in investing activities	(2,306,714)	(3,254,863)	(3,160,150)
Financing activities
Brokered deposit placement fee	(27,978)	(25,785)	(12,200)
Net increase in certificates of deposit	4,349,741	2,525,040	1,579,615
Net increase in other deposits	923,793	918,420	508,389
Borrowings collateralized by loans in securitization trusts - issued	1,105,594	1,891,027	1,440,127
Borrowings collateralized by loans in securitization trusts - repaid	(1,042,892)	(888,640)	(534,905)
Borrowings under Secured Borrowing Facility	297,800	300,000	300,000
Repayment of borrowings under Secured Borrowing Facility	(8,570)	(300,000)	(300,000)
Fees paid - Secured Borrowing Facility	(1,116)	(1,098)	(1,281)
Issuance costs for unsecured debt offering	0	0	(1,057)
Unsecured debt issued	0	0	197,000
Redemption of Series A Preferred Stock	0	0	(165,000)
Common stock dividends paid	(51,114)	0	0
Preferred stock dividends paid	(16,837)	(15,640)	(15,714)
Common stock repurchased	(167,201)	0	0
Net cash provided by financing activities	5,361,220	4,403,324	2,994,974
Net increase (decrease) in cash, cash equivalents and restricted cash	3,038,865	1,045,720	(336,335)
Cash, cash equivalents and restricted cash at beginning of year	2,681,895	1,636,175	1,972,510
Cash, cash equivalents and restricted cash at end of year	5,720,760	2,681,895	1,636,175
Cash disbursements made for:
Interest	666,018	472,459	269,017
Income taxes paid	201,792	228,074	282,278
Income taxes refunded	(853)	(13,449)	(1,401)
Reconciliation of the Consolidated Statements of Cash Flows to the Consolidated Balance Sheets:
Total cash, cash equivalents and restricted cash	$ 2,681,895	$ 1,636,175	$ 1,636,175