CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 487,476	$ 288,934	$ 250,327
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Provisions for credit losses	244,864	185,765	159,405
Deferred tax benefit	(63,301)	(58,752)	(88,732)
Amortization of brokered deposit placement fee	13,055	9,372	10,133
Amortization of Secured Borrowing Facility upfront fee	1,128	1,316	1,229
Amortization of deferred loan origination costs and loan premium/(discounts), net	10,905	8,258	5,811
Net amortization of discount on investments	1,712	2,082	2,043
Reduction of tax indemnification receivable	92,815	31,888	(12,283)
Depreciation of premises and equipment	13,829	11,171	9,592
Stock-based compensation expense	31,524	27,899	22,944
Unrealized losses (gains) on derivative and hedging activities, net	(1,353)	7,248	2,263
Gains on sale of loans, net	(2,060)	0	(230)
Losses on sales of securities, net	1,549	0	0
Other adjustments to net income, net	7,446	6,305	4,430
Changes in operating assets and liabilities:
Increase in accrued interest receivable	(864,461)	(703,081)	(582,361)
(Increase) decrease in other interest-earning assets	(5,571)	27,528	5,731
Decrease in tax indemnification receivable	35,989	59,633	59,633
Increase in other assets	(69,777)	(72,646)	(47,442)
Decrease in income tax payable, net	(79,693)	(19,687)	(20,647)
Increase in accrued interest payable	25,979	14,304	3,736
Increase in other liabilities	15,204	1,304	15,395
Total adjustments	(590,217)	(460,093)	(449,350)
Total net cash used in operating activities	(102,741)	(171,159)	(199,023)
Investing activities
Loans acquired and originated	(6,493,367)	(5,243,732)	(4,698,548)
Net proceeds from sales of loans held for investment	44,832	6,992	9,521
Proceeds from claim payments	54,659	49,146	64,869
Net decrease in loans held for investment	3,076,992	2,065,727	1,332,341
Purchases of available-for-sale securities	(15,876)	(78,327)	(55,767)
Proceeds from sales and maturities of available-for-sale securities	77,897	40,044	38,721
Total net cash used in investing activities	(3,254,863)	(3,160,150)	(3,308,863)
Financing activities
Brokered deposit placement fee	(25,785)	(12,200)	(4,371)
Net increase (decrease) in certificates of deposit	2,525,040	1,579,615	(434,740)
Net increase in other deposits	918,420	508,389	2,412,221
Issuance costs for collateralized borrowings	0	0	(2,090)
Borrowings collateralized by loans in securitization trusts - issued	1,891,027	1,440,127	1,775,692
Borrowings collateralized by loans in securitization trusts - repaid	(888,640)	(534,905)	(187,686)
Borrowings under Secured Borrowing Facility	300,000	300,000	376,325
Repayment of borrowings under Secured Borrowing Facility	(300,000)	(300,000)	(876,500)
Fees paid - Secured Borrowing Facility	(1,098)	(1,281)	(1,450)
Issuance costs for unsecured debt offering	0	(1,057)	0
Unsecured debt issued	0	197,000	0
Redemption of Series A Preferred Stock	0	(165,000)	0
Preferred stock dividends paid	(15,640)	(15,714)	(21,204)
Net cash (used in) provided by financing activities	4,403,324	2,994,974	3,036,197
Net increase (decrease) in cash, cash equivalents and restricted cash	1,045,720	(336,335)	(471,689)
Cash, cash equivalents and restricted cash at beginning of year	1,636,175	1,972,510	2,444,199
Cash, cash equivalents and restricted cash at end of year	2,681,895	1,636,175	1,972,510
Cash disbursements made for:
Interest	472,459	269,017	169,854
Income taxes paid	228,074	282,278	271,721
Income taxes refunded	(13,449)	(1,401)	(86)
Reconciliation of the Consolidated Statements of Cash Flows to the Consolidated Balance Sheets:
Cash, cash equivalents and restricted cash	$ 1,636,175	$ 1,972,510	$ 2,444,199